We are talking about the Galaxy M51. According to SamMobile, the firmware for the device came out with the build number M515FXXU2CUB7.
The software has added many innovations to Android 11, as well as the March security patch and the proprietary One UI 3.1 Core shell with a modified interface and other useful functions.
As usual, the system is distributed regionally. So you have to wait until the firmware gets to your device.