PHP message error

Hello, reviewing the logs we see this constant message.

2023/05/28 15:51:55 [error] 67719#67719: *1151534 FastCGI sent in stderr: "PHP message: PHP Warning: Undefined variable $dynpos in /www/site_530/public/wp-content/plugins/transmail/transMail.php on line 384 PHP message: PHP Warning: Undefined variable $dynfrom in /www/site_530/public/wp-content/plugins/transmail/transMail.php on line 384 PHP message: PHP Warning: Trying to access array offset on value of type null in /www/site_530/public/wp-content/plugins/transmail/transMail.php on line 384"