Catchable fatal error:

I am receiving the following error on each of the forms on my site

Warning: Invalid argument supplied for foreach() in /home/content/p3pnexwpnas05_data03/52/2397952/html/wp-content/plugins/constant-contact-api/vendor/constantcontact/constantcontact/src/Ctct/Services/ContactService.php on line 31

Catchable fatal error: Argument 2 passed to Ctct\Components\ResultSet::__construct() must be of the type array, null given, called in /home/content/p3pnexwpnas05_data03/52/2397952/html/wp-content/plugins/constant-contact-api/vendor/constantcontact/constantcontact/src/Ctct/Services/ContactService.php on line 34 and defined in /home/content/p3pnexwpnas05_data03/52/2397952/html/wp-content/plugins/constant-contact-api/vendor/constantcontact/constantcontact/src/Ctct/Components/ResultSet.php on line 27

The website is mlmethods.com to view. I really appreciate your help!

https://ww.wp.xz.cn/plugins/constant-contact-api/