Can I change the Boot Slot from Fastboot with a command?

Can I change the Boot Slot from Fastboot with a command? fastboot change slot switch slots ourselves using a Fastboot command Changing Android's Active Partition fastboot getvar currentslot 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

fastboot getvar currentslot I tried the fastboot update on windows on my thor device and am getting this error: Setting current slot to 'a' OKAY Finished

fastboot change slot  It can be very useful to know if partition slot A or slot B is currently active and you can learn 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