Need a simple help about Trello Token!

My company uses a thirt-party program that needs the access to one of my two trello accounts. (I get the App Key and the Token from here: Trello The problem is: my program only works on the App Key and Token generated with account A, not account B. However, I’d like to use account B.
I am not a programmer and to me the App Keys and Tokens of A and B look the same and have the same length. While I understand it’s not much information, could anyone give me some ideas or directions to start with? So that I know who or where I can ask for futher help.

Thank you very much!

A token is linked to a user, which means that your user needs to have the rights to make the changes that are required. In case the program needs to have access to a specific board, the member probably needs to be a full board member. So be sure both users have the same type of access, next to this there should be an error message somewhere explaining the reason why the token does not work. Try and find that and you probably know what the issue is.