Problems with access from Russia / "Error establishing a secure connection".

Proton VPN is blocked in Russia. Even if you download the program from a third-party resource, you won't be able to create an account. I had to use another VPN (a browser extension) to access the Proton VPN website and register. After entering my login and password in the program, nothing happens for a long time, and then a window appears with options for troubleshooting hypothetical problems.