Asus Prime H610M-E D4 CSM problem with the bios on my PC.

hello I have a problem with the bios on my PC....I want to upgrade from w10 to w11pro, I use an Asus Prime H610M-E D4 CSM. but there is a problem in the bios, namely in the secure boot. in the description of my secure boot system (legacy) I want to change it to (uefi) I have tried various methods, but the result is still the same, please help if you understand, because I have practiced the video on the YT channel but it is still the same hasn't changed...thanks for the help