[Решено] Translating Mail Chimp for WordPress form

Background of the issue:
I am trying to translate a MailChimp for WordPress form on a site under development. I have installed the plugin 'MailChimp for WordPress Multilingual' and applied the code indicated here (https://wpml.org/errata/mailchimp-for-wordpress-mc4wp-edit-link-from-translation-management-returns-a-broken-url/) to functions.php. The website is in Italian and the second language is English.

Symptoms:
Switching the language through the language flag in the top black stripe does not help. I also get this alert: 'WPML Translation Management > MailChimp Form in English is duplicated, please translate it separately.'

Questions:
How can I translate the MailChimp for WordPress form?
Why does switching the language through the language flag not work?
What does the alert 'WPML Translation Management > MailChimp Form in English is duplicated, please translate it separately' mean?