Problems adding users trial version

Hi,

I need help with an adobe sign account, I am testing all the functionalities and I am having trouble adding a user.

This is the error message that shows me when adding the user, this account has other adobe products associated with it.

Please help by releasing this account or domain to be able to add the user without problems to the adobe sign portal.

It can not be that with the trial version we have these problems, this does not help us decide to buy the tool

Waiting for your help and  your comments,