Errors using MailOptin

Hi, I’m getting error messages using MailOptin that are being displayed on the pages that I use with Elementor’s forms. Is there a solution to this?

Here are the error messages:

Deprecated: define(): Declaration of case-insensitive constants is deprecated in /home/learnc20/public_html/wp-content/plugins/mailoptin/mailoptin.php on line 19

Notice: Undefined index: mailchimp_api_key in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/MailChimpConnect/AbstractMailChimpConnect.php on line 37

Notice: Undefined index: drip_api_token in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/DripConnect/AbstractDripConnect.php on line 35

Notice: Undefined index: drip_account_id in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/DripConnect/AbstractDripConnect.php on line 36

Notice: Undefined index: sendlane_api_key in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/SendlaneConnect/AbstractSendlaneConnect.php on line 35

Notice: Undefined index: sendlane_hash_key in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/SendlaneConnect/AbstractSendlaneConnect.php on line 36

Notice: Undefined index: sendlane_domain in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/SendlaneConnect/AbstractSendlaneConnect.php on line 37

Notice: Undefined index: convertkit_api_key in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/ConvertKitConnect/AbstractConvertKitConnect.php on line 33

Notice: Undefined index: activecampaign_api_url in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/ActiveCampaignConnect/AbstractActiveCampaignConnect.php on line 33

Notice: Undefined index: activecampaign_api_key in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/ActiveCampaignConnect/AbstractActiveCampaignConnect.php on line 34

Notice: Undefined index: mailerlite_api_key in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/MailerliteConnect/AbstractMailerliteConnect.php on line 35

Notice: Undefined index: emailoctopus_api_key in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/EmailOctopusConnect/AbstractEmailOctopusConnect.php on line 33

Notice: Undefined index: sendinblue_api_key in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/SendinblueConnect/AbstractSendinblueConnect.php on line 37

Notice: Undefined index: getresponse_api_key in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/GetResponseConnect/AbstractGetResponseConnect.php on line 33

Notice: Undefined index: getresponse_is_360 in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/GetResponseConnect/AbstractGetResponseConnect.php on line 34

Notice: Undefined index: getresponse360_registered_domain in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/GetResponseConnect/AbstractGetResponseConnect.php on line 35

Notice: Undefined index: getresponse360_country in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/GetResponseConnect/AbstractGetResponseConnect.php on line 36

Notice: Undefined index: klaviyo_api_key in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/KlaviyoConnect/AbstractKlaviyoConnect.php on line 33

Notice: Undefined index: convertfox_api_key in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/ConvertFoxConnect/AbstractConvertFoxConnect.php on line 33

Notice: Undefined index: mailchimp_api_key in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/MailChimpConnect/AbstractMailChimpConnect.php on line 37

Notice: Undefined index: drip_api_token in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/DripConnect/AbstractDripConnect.php on line 35

Notice: Undefined index: drip_account_id in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/DripConnect/AbstractDripConnect.php on line 36

Notice: Undefined index: sendlane_api_key in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/SendlaneConnect/AbstractSendlaneConnect.php on line 35

Notice: Undefined index: sendlane_hash_key in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/SendlaneConnect/AbstractSendlaneConnect.php on line 36

Notice: Undefined index: sendlane_domain in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/SendlaneConnect/AbstractSendlaneConnect.php on line 37

Notice: Undefined index: convertkit_api_key in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/ConvertKitConnect/AbstractConvertKitConnect.php on line 33

Notice: Undefined index: activecampaign_api_url in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/ActiveCampaignConnect/AbstractActiveCampaignConnect.php on line 33

Notice: Undefined index: activecampaign_api_key in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/ActiveCampaignConnect/AbstractActiveCampaignConnect.php on line 34

Notice: Undefined index: mailerlite_api_key in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/MailerliteConnect/AbstractMailerliteConnect.php on line 35

Notice: Undefined index: emailoctopus_api_key in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/EmailOctopusConnect/AbstractEmailOctopusConnect.php on line 33

Notice: Undefined index: sendinblue_api_key in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/SendinblueConnect/AbstractSendinblueConnect.php on line 37

Notice: Undefined index: getresponse_api_key in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/GetResponseConnect/AbstractGetResponseConnect.php on line 33

Notice: Undefined index: getresponse_is_360 in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/GetResponseConnect/AbstractGetResponseConnect.php on line 34

Notice: Undefined index: getresponse360_registered_domain in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/GetResponseConnect/AbstractGetResponseConnect.php on line 35

Notice: Undefined index: getresponse360_country in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/GetResponseConnect/AbstractGetResponseConnect.php on line 36

Notice: Undefined index: klaviyo_api_key in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/KlaviyoConnect/AbstractKlaviyoConnect.php on line 33

Notice: Undefined index: convertfox_api_key in /home/learnc20/public_html/wp-content/plugins/mailoptin/src/connections/ConvertFoxConnect/AbstractConvertFoxConnect.php on line 33