MT300N-V2 uboot via uart

I am trying to access the uboot console via the uart on my MT300N v2. I found docs somewhere you had to press space to access it but that doesn’t seem to work, in the uart output I see it says type g1 but again that doesn’t seem to work.

What is the correct method for accessing the uboot console via the uart?

type gl, not g1.

And serial option should be like this: