I set up a new email server account with mailfence but Tbird will not accept the password from same

My former email provider ( first light) is a huge failing mess and they cannot fix my email service. I am trying to set up a new email address with mailfence as server/provider and Thunderbird as the ap. I set up a free account( plan to upgrade if all works well) at mailfence with a new email address, XXXX, and a macbook-pro generated password. I downloaded and opened Tbird and entered my new email address, but it would not accept the password for that mailfence email account. I also tried my former email service password which also failed.

 What can I do now?