Keyboard and mouse on xbox bannable?

it is up to the developer if they want mouse and keyboard if anyone is caught using mouse and keyboard it is a bannable offense from the game as it is not supported and the only way you can use mouse and keyboard is through using macros

Some games on the Xbox One or Series X|S do support keyboard and mouse. So if you use a keyboard and mouse just by plugging them into the usb ports on the Xbox console, then no it is not a bannable offense. It can be though if you use an unofficial adapter to play on games that do not support keyboard and mouse.

If the games support the keyboard and mouse, then they will detect them when you start the game. No bypass of any means is needed.

Do I need a “bypass” or anything else to use it with games ?

Using a keyboard and mouse on xbox one games that don't support it (unlike minecraft, which supports it) is bannable under the code of conduct regarding "unauthorized hardware".

Please use a controller.