[Bug] Warnings in file piwigopress_admin.php

My Server shows many uninitialized variables in piwigopress_admin.php, please fix it asap

Notice: Undefined index: piwigopress_url in /var/www/vhosts/domain.tld/wp-content/plugins/piwigopress/piwigopress_admin.php on line 19
Notice: Undefined index: thumbnail_size in /var/www/vhosts/domain.tld/wp-content/plugins/piwigopress/piwigopress_admin.php on line 20
Notice: Undefined index: desc_check in /var/www/vhosts/domain.tld/wp-content/plugins/piwigopress/piwigopress_admin.php on line 21
Notice: Undefined index: photo_class in /var/www/vhosts/domain.tld/wp-content/plugins/piwigopress/piwigopress_admin.php on line 22
Notice: Undefined index: link_type in /var/www/vhosts/domain.tld/wp-content/plugins/piwigopress/piwigopress_admin.php on line 23
Notice: Undefined index: piwigopress_url in /var/www/vhosts/domain.tld/wp-content/plugins/piwigopress/piwigopress_admin.php on line 25
Notice: Undefined index: piwigopress_url in /var/www/vhosts/domain.tld/wp-content/plugins/piwigopress/piwigopress_admin.php on line 19
Notice: Undefined index: thumbnail_size in /var/www/vhosts/domain.tld/wp-content/plugins/piwigopress/piwigopress_admin.php on line 20
Notice: Undefined index: desc_check in /var/www/vhosts/domain.tld/wp-content/plugins/piwigopress/piwigopress_admin.php on line 21
Notice: Undefined index: photo_class in /var/www/vhosts/domain.tld/wp-content/plugins/piwigopress/piwigopress_admin.php on line 22
Notice: Undefined index: link_type in /var/www/vhosts/domain.tld/wp-content/plugins/piwigopress/piwigopress_admin.php on line 23
Notice: Undefined index: piwigopress_url in /var/www/vhosts/domain.tld/wp-content/plugins/piwigopress/piwigopress_admin.php on line 25
Notice: Undefined index: piwigopress_url in /var/www/vhosts/domain.tld/wp-content/plugins/piwigopress/piwigopress_admin.php on line 19
Notice: Undefined index: thumbnail_size in /var/www/vhosts/domain.tld/wp-content/plugins/piwigopress/piwigopress_admin.php on line 20
Notice: Undefined index: desc_check in /var/www/vhosts/domain.tld/wp-content/plugins/piwigopress/piwigopress_admin.php on line 21
Notice: Undefined index: photo_class in /var/www/vhosts/domain.tld/wp-content/plugins/piwigopress/piwigopress_admin.php on line 22
Notice: Undefined index: link_type in /var/www/vhosts/domain.tld/wp-content/plugins/piwigopress/piwigopress_admin.php on line 23
Notice: Undefined index: piwigopress_url in /var/www/vhosts/domain.tld/wp-content/plugins/piwigopress/piwigopress_admin.php on line 25
Notice: Undefined index: piwigopress_url in /var/www/vhosts/domain.tld/wp-content/plugins/piwigopress/piwigopress_admin.php on line 19
Notice: Undefined index: thumbnail_size in /var/www/vhosts/domain.tld/wp-content/plugins/piwigopress/piwigopress_admin.php on line 20
Notice: Undefined index: desc_check in /var/www/vhosts/domain.tld/wp-content/plugins/piwigopress/piwigopress_admin.php on line 21
Notice: Undefined index: photo_class in /var/www/vhosts/domain.tld/wp-content/plugins/piwigopress/piwigopress_admin.php on line 22
Notice: Undefined index: link_type in /var/www/vhosts/domain.tld/wp-content/plugins/piwigopress/piwigopress_admin.php on line 23
Notice: Undefined index: piwigopress_url in /var/www/vhosts/domain.tld/wp-content/plugins/piwigopress/piwigopress_admin.php on line 25

https://wordpress.org/plugins/piwigopress/