What kind of visas do non-EU porn stars get when filming for EU studios? I'm mainly referring to Russian, Ukrainian and American performers.

To my knowledge, they will either need some type of work visa sponsored by the porn studio, or some kind of freelance visa.

I'm wondering how easy or difficult it is for a company based in Czechia, for example, to sponsor a visa for a non-EU performer. And how the process goes if the performer is unknown or a first timer. What are the most lenient countries in Europe when it comes to sponsor immigrants for this purpose?