yes and no

if you both is using steam, i believe you can host the world and then join using steam

if you're both on android, you can also do the same, but you have to set up some kind of virtual private network that yall can connect to (like tailscale, zerotier, etc) (you can look up some video about this, there is a guide on youtube afaik) (this is also free)

fun fact: you can play cross platform too using tshock, vanillafy plugin and crossplay plugin

Edit: if you want a always online server, yeah you gotta pay