How add more format to the same 3D object ? to sell?

hello.
I add a photo here.
wondering how I can add more formats to my object to sell.
note: I already have the formats, but my question is, how do I end up adding them?

If you sell your model, go to EDIT PROPERTIES and click on
UPLOAD FILE (in red on the follow picture) and choose the zipped file in which you will have put your 3D files.

If you don’t sell your model you must have a pro account.

You can read this topic : Upload multiple files in different formats and https://help.sketchfab.com/hc/en-us/articles/202508836-Uploading-3D-Models