Drunk & Root

u could prob find a way to do this with nextcloud i saw smth like this on fdroid for nextclouf

synapse can be resource intensive but u can conduwuit or now tuwunel and its pretty lightweight https://github.com/girlbossceo/conduwuit https://github.com/matrix-construct/tuwunel

i mean cant go wrong with a self hosted matrix instance im pretty sure theres some managed hosts that make the process eaiser i dont know if this is what your looking for but cant go wrong with it