Plugin not work with PHP 8.1.1

Hello,

my provider set php 8.1.1 to my site. When I send a mail over contactform the following is output in the wordpress debug.log:

[06-Oct-2022 13:46:30 UTC] PHP Fatal error:  Uncaught TypeError: implode(): Argument #2 ($array) must be of type ?array, string given in /var/www/web/html/mysite/wp-content/plugins/contact-form-7-to-database-extension/CF7DBPlugin.php:849
Stack trace:
#0 /var/www/web/html/mysite/wp-content/plugins/contact-form-7-to-database-extension/CF7DBPlugin.php(849): implode(Array, ', ')
#1 /var/www/web/html/mysite/wp-content/plugins/contact-form-7-to-database-extension/CFDBIntegrationContactForm7.php(55): CF7DBPlugin->saveFormData(Object(stdClass))
#2 /var/www/web/html/mysite/wp-includes/class-wp-hook.php(309): CFDBIntegrationContactForm7->saveFormData(Object(WPCF7_ContactForm))
#3 /var/www/web/html/mysite/wp-includes/class-wp-hook.php(331): WP_Hook->apply_filters('', Array)
#4 /var/www/web/html/mysite/wp-includes/plugin.php(524): WP_Hook->do_action(Array)
#5 /var/www/web/html/mysite/wp-content/plugins/contact-form-7/includes/submission.php(772): do_action_ref_array('wpcf7_before_se...', Array)
#6 /var/www/web/html/mysite/wp-content/plugins/contact-form-7/includes/submission.php(101): WPCF7_Submission->before_send_mail()
#7 /var/www/web/html/mysite/wp-content/plugins/contact-form-7/includes/submission.php(33): WPCF7_Submission->proceed()
#8 /var/www/web/html/mysite/wp-content/plugins/contact-form-7/includes/contact-form.php(1047): WPCF7_Submission::get_instance(Object(WPCF7_ContactForm), Array)
#9 /var/www/web/html/mysite/wp-content/plugins/contact-form-7/includes/rest-api.php(357): WPCF7_ContactForm->submit()
#10 /var/www/web/html/mysite/wp-includes/rest-api/class-wp-rest-server.php(1143): WPCF7_REST_Controller->create_feedback(Object(WP_REST_Request))
#11 /var/www/web/html/mysite/wp-includes/rest-api/class-wp-rest-server.php(990): WP_REST_Server->respond_to_request(Object(WP_REST_Request), '/contact-form-7...', Array, NULL)
#12 /var/www/web/html/mysite/wp-includes/rest-api/class-wp-rest-server.php(414): WP_REST_Server->dispatch(Object(WP_REST_Request))
#13 /var/www/web/html/mysite/wp-includes/rest-api.php(394): WP_REST_Server->serve_request('/contact-form-7...')
#14 /var/www/web/html/mysite/wp-includes/class-wp-hook.php(307): rest_api_loaded(Object(WP))
#15 /var/www/web/html/mysite/wp-includes/class-wp-hook.php(331): WP_Hook->apply_filters('', Array)
#16 /var/www/web/html/mysite/wp-includes/plugin.php(524): WP_Hook->do_action(Array)
#17 /var/www/web/html/mysite/wp-includes/class-wp.php(398): do_action_ref_array('parse_request', Array)
#18 /var/www/web/html/mysite/wp-includes/class-wp.php(770): WP->parse_request('')
#19 /var/www/web/html/mysite/wp-includes/functions.php(1330): WP->main('')
#20 /var/www/web/html/mysite/wp-blog-header.php(16): wp()
#21 /var/www/web/html/mysite/index.php(17): require('/var/www/web...')
#22 {main}
  thrown in /var/www/web/html/mysite/wp-content/plugins/contact-form-7-to-database-extension/CF7DBPlugin.php on line 849

If I set the PHP back to 7.3.4 everything works as usual. On 28.11.2022 the version 7.3.4 is dropped by my provider. How do I get working contact pages?
Thanks for your help.