3D stl imported into standard easel file

So I’m trying to figure out how to import a stl file into an existing regular easel file that I created to combine into one project. Such as a flag with Stars and Stripes carved and a 3D trident added to them. Is this doable on Easel? Thanks for any help you can give.

simply put: No

Easel does 3d via a single STL file OR 2D/2.5D via the standard user design process.
The 2 processes do not integrate with each other.
However there are ways of thinking outside the box to combine them in a more manual method. Like Cutting a pocket for the 3d item to attach into on the 2.5D flag and then carving the 3D trident separately and adhering it onto the flag within the pocket…
I’ve done this sort of thing on other flags years ago…

That’s a good idea thank you!