Hi there,
We recently moved our 10 years old discourse outfit to a hosted plan.
The usual api endpoints for invites GET “/invites.json” & POST “/invites” now return 404
This topic doen’t seem to be covered in the documentation
Would love an expert answer 
Kind regards
The API endpoints do not change, no.
But depending on how old your hosted site was the authentication method may have changed; check the documentation to ensure it is still correct.
And if you’re hosted with us, you can email us for support with your specific site.
Either way, glad to hear you’ve been using Discourse for this long! 
That suggests that your API key is invalid. Did you restore your old database?
You can try generating a new api key or seeing if the old one got invalidated for some reason.