How to change the current active partition 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

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 get active slot being installed to the opposite partition than you're currently on So active and you can

fastboot change slot Android phones can now have an A and a B partition system for the OS and we can use this fastboot command to check and see which slot is currently active