How to do keyboard input handling in C in UEFI?

Question

C++ / C#

How can keyboard input be handled? in the BIOS, interrupts were used in 16-bit mode for this, as well as in / out ports and the keyboard buffer in a protected (at least I used them, it was enough for small low-level programs) In UEFI, for some unknown reason, I read the keyboard buffer couldn't. I heard that UEFI services are used there for some needs. So: what service allows you to enter data from the keyboard? And what to do after ExitBootServices?