How to change the current active partition slot?

How to change the current active partition slot? fastboot get active slot But I want without fastboot command My usecase is the bootloader need to check the currect active slot and set the proper suffix How can I do fastboot change slot I am trying to root my Xiaom mi a2 phone But i am stuck on changing the active partition When i enter fastboot set_active b it doesnt

fastboot change slot Boot your smartphone into Fastboot Mode · Now, connect your smartphone to the PC using a USB cable · Open a Command Prompt, Terminal, or

fastboot getvar currentslot 查詢目前使用那個槽， 看目前的slot是a還是b，一般都是a。1$ sudo fastboot getvar current-slot 參考 adb 1 Switching the slot using fastboot Switching the slot via fastboot works if TWRP is installed in the boot partition · 2 Switching the slot