fastboot set_active command does not exist

fastboot set_active command does not exist fastboot change slot fastboot recovery mode that shows signal strength and IMEI No They showed as having a uSD slot, so hopefully they have the correct chipset fastboot getvar currentslot stack trace: Error: failed to set active slot: Error: {error:{code:1,cmd:fastboot --set-active=b},stderr: waiting for any device >

fastboot getvar currentslot Sustainable Impact Creating lasting, positive change for the planet, our people, and the communities where we live, work, and do business

fastboot change slot 8GB MEMORY Built-in Wifi Built-in Camera with NumPad Flat Keyboard VGA SLOT HDMI SLOT SD CARD SLOT DVD DRIVE USBLAN PORT stack trace: Error: failed to set active slot: Error: {error:{code:1,cmd:fastboot --set-active=b},stderr: waiting for any device >