Android fastboot 查詢當前使用的ab槽

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

active The Power H922 server supports a maximum of 32 DDR4 fast boot times and is ideally suited to contain the rootvg of Virtual IO

fastboot getvar currentslot Fastboot commands ; getvar super-partition-name, Returns the name of the super partition The name includes the current slot suffix if the super partition is an

fastboot_ error_ failed to identify current 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