Create your extension first obviously, publish it to Github, Bitbucket, or other online git cloud.

Then send an email to any of the maintainers with the link and they will review and add your extension to the list of standard extensions in pyRevit repository.

Here are the information that is needed

This information will be stored in this JSON file and is used by the extension manager or pyRevit CLI to find information about your extension and install on user machine.

    "builtin": "False",
    "default_enabled": "True",
    "type": "extension",
    "rocket_mode_compatible": "False",
    "name": "PyRevitPlus",
    "description": "Extensions for PyRevit",
    "author": "Gui Talarico",
    "author_profile": "<>",
    "url": "<>",
    "website": "<>",
    "image": "",
    "dependencies": []