MMORPG - Epic Account game connection - server management

Hello,

I take information for create a little MMORPG with Unreal Engine 5.

For prepare it, I search information about some asking:

If we use the Epic Game Launcher and put our game in the shop of the official Epic Game, That mean people use their own account for connect to the game.

So: What do we need to make the connection between epic game player and our server?

Another linked asking: DO we manage our own server or it’s Epic game that manage the hosting of the server (and all the fee that use for running this kind of game?)

Or do we need to create our own launcher, or own player database that link with the epic game database for check the purchase of the game and other feature and manage the hosting our own server?

Thank you.