You should defintely have a look at Swagger
https://swagger.io/solutions/api-documentation/
+1 for Integromat they've built an absolutely amazing integration ecosystem, with more or less endless possibilities.
The Slack integration, can setup a Zoom call directly in a channel or DM
+1 for x.ai I'm a quite happy user as well
The "perfect" ticketing system I still really don't think is available out there ;) There's a lot of hype amongst the traditional players, Zendesk including towards pivoting more towards true…
Check out https://www.getmailbird.com/ as well, it's neat and tidy with nice various OS support.