Can't unlock bootloader

[Habsforever]

I'm trying to get A15 on my Surface Duo 2 but i'm having issues.

When trying to boot to fastboot (adb reboot fastboot), when trying to run "fastboot delete-logical-partition system_ext", I get the below error
Deleting 'system_ext' FAILED (remote: 'Command not available on locked devices')
fastboot: error: Command failed

If I boot to the bootloader, I get a different error when trying to delete system_ext.
Deleting 'system_ext' FAILED (remote: 'unknown command')
fastboot: error: Command failed

I tried doing a factory reset but after, no change. I have also enabled developer mode with OEM unlocking and USB debugging enabled. Anyone have any ideas how I can resolve this? Thanks in advance!

[MissingxLink]

adb reboot bootloader
fastboot flashing unlock

[Habsforever]

Thanks so much! That fixed it but now when trying to image (fastboot flash system aosp-arm64-ab-gapps-15.0-20241223.img), I get a low disk space error.

Resizing 'system_b' FAILED (remote: 'Not enough space to resize partition')
fastboot: error: Command failed

[Habsforever]

Nevermind, I followed Archfx suggestion posted in #36 (comment)