Double opt in doesn’t work

Hello

I manage to set up the plugin and some of the functions work.
But when i want a double opt in it doesn’t work.

The contact doesn’t get a opt in mail.
When i take away the option Double Opt-in in elementor forms the contact adds to the list. But when i check the Double opt-in sendinblue doesn’t get the information.

Do you have any idea why?

Greetings