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Install marketplace plugin on source?

Question how does one get a marketplace bought item that uses a plugin to show up on source built engine?

Move plugin manually from Epic Games\4.XX\Engine\Plugins\Marketplace to your source engine plugins folder or your project/plugins folder.

But I do not have 4.24 version as binaries in my Epic Launcher, so I have to download 10 gb+ 4.24 version just so that I can download compatible plugins ?

You can configure installer options to download only minimum binary editor, it’s around 4gb.