OK I solved it: the user agent is identifies your device and browser to the web server. So on my computer, I login to Twitter. If it works, on the same device and browser, google what is my user agent. It gives you a string like this:
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.141 Safari/537.36
Then on your mobile phone, do the same thing: login to Twitter. If it logins successfully, google the useragent. Copy and paste the two strings into TAP5. Afterwards it works perfectly for me.
My user agent works for me but might not work for everyone:
1) on your device, go to Twitter on your browser
2) login and see if it lets you log in
3) if #2 is successfully logged in, on the same browser, go to google search
4) google search "my user agent" and it should give you a string of text similar to what I posted above
5) use that "good" user agent in your TAP
Repeat on the mobile phone, and I got it to work.
Good luck
You can find thousands of user agents here. Paste them one by one in and add them. Then use the option Test Mobile UserAgent. It will verify which ones are valid to work with TAP.
https://developers.whatismybrowser.com/useragents/explore/hardware_type_specific/mobile/7
I was having issues with TAP4 suddenly removing all of them, no matter what I entered. I reached out to support and they just suggested I use desktop instead (which has never worked as well as mobile for TAP). Seems to work with version 5 though. Now the issue I have is "Network Error" with everything I try to do outside that.