With the right hardware, there are even ways to do this just by configuring the laptop's USB port into gadget mode and then... plugging it in.
(I would use it to use a laptop keyboard on a headless computers).
I am looking for an easy solution, it does not have to be the cheapest.
ChatGPT points me to Arduino, but as far as I can see, there's no arduino with 2 usb ports. It also points me to Raspery pi zero, but that's a computer, not a microcontroller, so not sure if it's suitable.
If anyone with experience can give me some pointers, it would be greatly appreciated!