You’re were right. My Twilio webhook was set to POST. I changed that to GET and it now returns!
BUT, and this has me scratching my head. It returns ‘Hello from Flask!.‘ That phase does not exists anywhere in my python code. Also, I once deleted all the code in flask_app.py. I then texted my Twilio number to test and python/flask again returned ‘Hello from Flask!’
So I’m at a hard stop at this point. I feel like I’m almost there though. For what it’s worth, I’m also now a paying customer at pythonanywhere. I was concerned that perhaps free accounts would not return. Still, no matter what it seems like my app will return ‘Hello from Flask!’ and my python code is not processed. (App is running btw) Hmm.. Head scratching.