While it was our intention to release PROVIDER on both Ubuntu and Windows, Steam's system of supporting Ubuntu with outdated libraries has led to support issues with PROVIDER. This can be fixed on certain systems by overriding Steam's libraries in favor of the local OS's, but this fix is not universal and spins out into a web of support issues that make us uncomfortable with calliing Ubuntu "supported" in Steam.
I apologize to any Ubuntu players, we'll be releasing the Ubuntu version on itch with our dependencies listed next week. Please request a refund if you planned to play on Ubuntu.
Thanks,
Wyatt