Licensing question

Hello everyone.

I’m really new here but I found this forum useful to ask something.

I was looking for a 1st/3rd person engine to start a new business but I wonder if GPL2 allows me or not.
I dropped other engines until I remembered this engine.

I need the engine (ioquake3) and I have my own content (maps, textures, models) and game dll (gameplay).
The game would be free to use but… I want to include microtransactions.

So you can play it for free and also you can get in-game exclusive stuff with real money.

Can I do that under ioquake3 GPL2 licensing?

What if I add some modifications to ioquake3 on my game?

Thanks in advance

You can use ioquake3 for commercial projects, you would be required to release the source code to your changes to the engine but you would still commercially license the content.