M12 Boot menu

Power off your device, Connet your device's usb cable with computer, Press and hold Volume up and power button, after power on release only power key,
Try it brow

When u say boot menu, I'm assuming you mean recovery mode?

Here's an easy tutorial
https://www.hardreset.info/devices/samsung/samsung-galaxy-m12/recovery-mode/

If i helped in any way, please consider hitting the 3 dot menu on my comment and accepting it as a solution

Power off your device
Then press and hold power+vol.up key untill samsung logo appear
Still hold after samsung logo disappear you can 3 release.and now you are in recovery mode

In Android 11 and later, for Exynos models you need your phone's USB C port connected to another device (can be a laptop, PC, or even just a USB C headset/headphone) to go into the recovery mode (boot menu in your words).

Only press power menu..
If this comment helped pls accept as a solution