Creation of a custom Actor type in a plugin? (not C++ class for the project but plugin)

I’m wondering where I should start to code a new kind of Actor, probably the most similar thing could be an spherical trigger, but I didn’t find any documentation, I just only find how to add a C++ Class to the project but as I said I need it in a plugin instead linked to the project itself.

Thank you in advance for any tip.

Plugins | UE4 Documentation