Type of license 2D20


I wanted to inquire about the type of license the 2d20 system would have.
I was designing an RPG and recently discovered your material. I wish I had known about it earlier because I like :slight_smile: , but it happens that the system I was creating looks a lot like the 2d20 basics.
Although they use d10 and a different way of generating the dice pool, they are also roll trying to score less than X for success. And with the additional successes you can use them for the narration and for a common pool for all the players, the same for the Master.
All this I was developing but I see that I am a few years late.
So, I am curious to know in what situation is the license of the 2d20 system, and if with the differences that mine has and without repeating concepts there would be no problem when marketing it.

(Translation made thanks to Google, translator, if something is not understood it is the fault of another XD)