GOOGLE PLEASE HELP

I got this app to talk to a friend I made online. The app worked perfectly fine until one day, it wouldn’t send my messages. I tried tapping the message over and over but it didn’t work. I’ve tried signing in and out of my account multiple times but that hasn’t worked either. My device and internet both work perfectly fine, so it’s not that. I don’t know if it’s just me having this problem but please fix it. I just want to talk to my friend.
(P.S. I’m going to keep sending this review until someone answers why this is happening or until my google hangouts decides to work. Not trying to spam you or anything but I just don’t know what to do.)

Cupcake Kitty ? about Hangouts, v21.0.0