modules don’t work

Hi, I have encountered a problem with using modules in the plugin. I would simply like a popup in which the user can register for one of our particular newsletters, which makes them receive an immediate 10% discount, as soon as they are registered in the newsletter. I set everything as it should but when I try it gives me the following error: An error has happened while performing a request, please try again later.

I created the “newsletter” list and the email that is sent with the discount code. Nothing seems to work. I would like to understand if it is an interaction problem. I wish that non-logged in users could safely subscribe to the newsletter

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