Upload an avatar with api

Hello I am currently developing a gravatar like, but I cannot find any way to modify a user’s avatar.

is there a way?

I am currently abroad, but I highly guess that the avatar is controlled by the user backend (you might want to check that or anyone can correct me there). If that is true, you would need to check with each backend individually (e.g. local users vs. LDAP users etc).

You can check if there is an API provided but I guess not. It might be there is an API but I do not know for sure.