C:\Users\aweso>cd C:\Games\Mod Files\platform-tools

C:\Games\Mod Files\platform-tools>adb devices
List of devices attached
PM1LHMA832904194        device


C:\Games\Mod Files\platform-tools>adb reboot bootloader

C:\Games\Mod Files\platform-tools>fastboot devices
PM1LHMA832904194        fastboot

C:\Games\Mod Files\platform-tools>fastboot getvar current-slot
current-slot: _a
Finished. Total time: 0.010s

C:\Games\Mod Files\platform-tools>fastboot flash boot_b twrp-3.2.3-0-mata.img
fastboot: error: Couldn't parse partition size '0x'.

C:\Games\Mod Files\platform-tools>fastboot flash boot_a twrp-3.2.3-0-mata.img
fastboot: error: Couldn't parse partition size '0x'.

C:\Games\Mod Files\platform-tools>fastboot flash boot twrp-3.2.3-0-mata.img
Sending 'boot__a' (48712 KB)                       OKAY [  1.223s]
Writing 'boot__a'                                  FAILED (remote: 'No such partition.')
fastboot: error: Command failed

C:\Games\Mod Files\platform-tools>fastboot --set-active=b
Setting current slot to 'b'                        OKAY [  0.036s]
Finished. Total time: 0.052s

C:\Games\Mod Files\platform-tools>fastboot flash boot twrp-3.2.3-0-mata.img
Sending 'boot__b' (48712 KB)                       OKAY [  1.222s]
Writing 'boot__b'                                  FAILED (remote: 'No such partition.')
fastboot: error: Command failed

C:\Games\Mod Files\platform-tools>fastboot flash boot_other twrp-3.2.3-0-mata.img
Sending 'boot_other' (48712 KB)                    OKAY [  1.232s]
Writing 'boot_other'                               FAILED (remote: 'No such partition.')
fastboot: error: Command failed

C:\Games\Mod Files\platform-tools>fastboot --set-active=a
Setting current slot to 'a'                        OKAY [  0.113s]
Finished. Total time: 0.136s

C:\Games\Mod Files\platform-tools>fastboot flash boot_other twrp-3.2.3-0-mata.img
Sending 'boot_other' (48712 KB)                    OKAY [  1.222s]
Writing 'boot_other'                               FAILED (remote: 'No such partition.')
fastboot: error: Command failed

C:\Games\Mod Files\platform-tools>fastboot flash boot_a twrp-3.2.3-0-mata.img
fastboot: error: Couldn't parse partition size '0x'.

C:\Games\Mod Files\platform-tools>