The last time I've rented a Minecraft server was probably over 10 years ago, and as far as I can tell, at the time having to upload stuff through ftp was normal.
Although reading this thread has also taught me that I know nothing about how deployment works and I need to catch up on that.
The most reliable way to communicate bases would probably be using unary.
Now if your alien is using unary, that might not work, but it should for all higher bases.
The most lifelike part of VRchat is the social anxiety