Getting Error

Hi i am getting this error:

Plugin could not be activated because it triggered a fatal error.
Warning: include_once(/var/www/xxxx/wp-content/plugins/wp-sms-pro/gateway/gateways/msg91.class.php): failed to open stream: No such file or directory in /var/www/xxxx/assets/plugins/wp-sms/wp-sms.php on line 35

Warning: include_once(): Failed opening ‘/var/www/xxxx/wp-content/plugins/wp-sms-pro/gateway/gateways/msg91.class.php’ for inclusion (include_path=’.:/usr/share/php:/usr/share/pear’) in /var/www/xxxx/assets/plugins/wp-sms/wp-sms.php on line 35

Fatal error: Class ‘msg91’ not found in /var/www/xxxx/assets/plugins/wp-sms/wp-sms.php on line 38

https://wordpress.org/plugins/wp-sms/