I just got my RT76P and tried programming the bandwidth changes with the latest software. It wouldn't do it, but I followed an earlier tip to load the old software, v1-4-5 setup, and it worked fine in that version. Also, Retevis is apparently updating the software and Lucy sent me a newer version (using one of their apparently temporary links) with 'developing' in the name. It appears that version will also let you add channels. Here's the link to the 2MB field download that expires in 5 days.
https://wetransfer.com/downloads/9c259b5366e356b01cd5b630a3bb35d420210525101916/cc4ea3ba70abd74e27276f8a21b9273520210525102016/34bb46?utm_campaign=WT_email_tracking&utm_content=general&utm_medium=download_button&utm_source=notify_recipient_email
atnbirdie got a reaction from Extreme in Retevis RT76P programming
