Error submitting additional info: permission denied to update country_of_tax_residence or not recognized

I have registered to your Trader API platform and am trying to buy algo trader plus membership, however I get the following error message while trying to do so;

Error submitting additional info: permission denied to update country_of_tax_residence or not recognized

To my knowledge, my country is allowed in Alpaca. Should I be verified to buy algo trader plus or sth?

Please help.