Can you defeat the Ender dragon in Minecraft with multiple players?

The three of us play on XBox and PC and have found the end portal, can we all go in together, one after the other, as with the Nether portal? Can you fight the kite in threes at all? Do you have to pay attention to anything else in multiplayer?

Who gets the achievement? Anyone or the one who fired the last shot?

Yes you can do. Everyone should get the achievement. If not, you can also re-summon the dragon.

As soon as we have enough eyes for the portal and that is open, just one by one?

You can get in there together & usually get the trophy all.

Of course you can go in together

Yes exactly