Warning: Undefined array key "email" in /usr/home/uhmtiss/domains/mailchimp.poligrand.pl/public_html/index.php on line 8

Fatal error: Uncaught InvalidArgumentException: Missing the required parameter $subscriber_hash when calling  in /usr/home/uhmtiss/domains/mailchimp.poligrand.pl/public_html/vendor/mailchimp/marketing/lib/Api/ListsApi.php:10986
Stack trace:
#0 /usr/home/uhmtiss/domains/mailchimp.poligrand.pl/public_html/vendor/mailchimp/marketing/lib/Api/ListsApi.php(10940): MailchimpMarketing\Api\ListsApi->setListMemberRequest('8bc923d660', NULL, Array, NULL)
#1 /usr/home/uhmtiss/domains/mailchimp.poligrand.pl/public_html/vendor/mailchimp/marketing/lib/Api/ListsApi.php(10934): MailchimpMarketing\Api\ListsApi->setListMemberWithHttpInfo('8bc923d660', NULL, Array, NULL)
#2 /usr/home/uhmtiss/domains/mailchimp.poligrand.pl/public_html/index.php(18): MailchimpMarketing\Api\ListsApi->setListMember('8bc923d660', NULL, Array)
#3 {main}
  thrown in /usr/home/uhmtiss/domains/mailchimp.poligrand.pl/public_html/vendor/mailchimp/marketing/lib/Api/ListsApi.php on line 10986