Connect Camtasia to YouTube branded channel -- 2

I have been unable to export my videos from Camtasia to my new YouTube channel, which is branded. I keep getting error messages such as those pasted below. I can provide any sign in information or access you need to make this work. I just need to be able to export my videos to YouTube.

PLEASE RESPOND TO THIS PROPOSAL WITH A BRIEF EXPLANATION OF YOUR EXPERIENCE USING CAMTASIA!

I am using a new account and channel I just created on YouTube (Email address info[at]visionarysociety.org and YouTube channel Creating Visionary Society).

Error messages:
From Camtasia
Unexpected YouTube Response
Please try uploading again. If this recurs, see YouTube's help resources at https://www.google.com/support/youtube/

From Google or YouTube
Authorization Error
Error 400: invalid_request
Account restricted

My Camtasia version is 2021.0.11