How to change Android system boot slot form A to B

How to change Android system boot slot form A to B fastboot get active slot slots ourselves using a Fastboot command The Real Reason Why Music Is Getting Worse fastboot getvar currentslot The inactive slot contains an older bootloader whose anti-rollback version has not been incremented If the active slot is then flashed with a build that fails

fastboot getvar currentslot Flash all partitions from $ANDROID_PRODUCT_OUT On AB devices, flashed slot is set as active Secondary images may be flashed to inactive slot

fastboot_ error_ failed to identify current slot If you device randomly got stuck in fastboot after a reboot, that means the counter hit zero and the bootloader marked your slot as unbootable  So i decided to flash twrp into a boot slot via fastboot then, i set the active-slot to that but then I still don't get twrp idk why Now, I can get into