I have found issue now the plugin is conflict with wp smtp pro plugin.
we are getting below error
PHP Fatal error: Uncaught TypeError: Argument 3 passed to GuzzleHttp\Client::request() must be of the type array, string given, called in /home/.cloudwaysapps.com/eptnkcmecv/public_html/wp-content/plugins/wp-mail-smtp-pro/vendor/guzzlehttp/guzzle/src/Client.php on line 95 and defined in /home/.cloudwaysapps.com/eptnkcmecv/public_html/wp-content/plugins/wp-mail-smtp-pro/vendor/guzzlehttp/guzzle/src/Client.php:179
Uncaught TypeError: Argument 3 passed to GuzzleHttp\\Client::request() must be of the type array, string given, called in /home/.cloudwaysapps.com/eptnkcmecv/public_html/wp-content/plugins/wp-mail-smtp-pro/vendor/guzzlehttp/guzzle/src/Client.php on line 95 and defined in /home/.cloudwaysapps.com/eptnkcmecv/public_html/wp-content/plugins/wp-mail-smtp-pro/vendor/guzzlehttp/guzzle/src/Client.php:179\nStack trace:\n#0 /home/.cloudwaysapps.com/eptnkcmecv/public_html/wp-content/plugins/wp-mail-smtp-pro/vendor/guzzlehttp/guzzle/src/Client.php(95): GuzzleHttp\\Client->request(‘createRequest’, ‘GET’, ‘https://api.con…’)\n#1 /home/.cloudwaysapps.com/eptnkcmecv/public_html/wp-content/plugins/constant-contact-forms/vendor/constantcontact/constantcontact/src/Ctct/Services/BaseService.php(65): GuzzleHttp\\Client->__call(‘createRequest’, Array)\n#2 /home/.cloudwaysapps.com/eptnkcmecv/public_html/wp-content/plugins/constant-contact-forms/vendor/constantconta…’,