Could you post the game link so we can have a look at the chat?
Also, if you feel a Adolf Hitler has crossed the line with what he/she said in chat, do not hesitate to report this player.
You can report via https://www.warzone.com/Report?p=74114191260
Please note that naming yourself after a world leader is not against the rules, even if the person they named themselves after did a lot of bad things. Therefor the name 'Adolf Hitler' is allowed by the Warzone rules.