It’s surprisingly hard to craft a search query to get a nice link. Nevertheless, here[1] you can find a somewhat oblique reference.

[1] https://asiatimes.com/2022/07/how-china-could-leapfrog-us-ch...

Ah, I think that’s referring to some of the suppliers (and IP) ASML uses to build its machines, not the EUV tech itself.

If you think about it, ASML wouldn’t be this critical to semiconductor fabrication if it didn’t control the patents for its core tech.