I get an error through process of GTIN exemption

Hello, I went through all process of GTIN exemption many times but instead of GTIN exemption, I received additional placement of the products at my account. I need to GTIN exemption to use Printful as POD company, but the problem is:

when apply for the GTIN exemption I get an error. "Not Found. The page you requested was not found."

Probably this happens because I have the wrong type of account. Probably I might need to change my hand maid account to another type of account. I don't know what kind of account I have but it's pro.

What I do:

1.Start the exemption process - https://sellercentral.amazon.com/productclassify/handmade?ref_=xx_addlisting_dnav_xx

2. Choose the product type - t-shirt

etc. and finally I get I see that another Listing was created at my account. It's not what I need!

If I follow instructions by Printful and click on request GTIN exemption - I get Error "Not Found. The page you requested was not found."

Printful is connected with my Amazon account and synchronized but I can start add product to Amazon but after 10 min I get "You need to have "GTIN exemption".

Any suggestion would be very appreciated!