GL-B1300 GPIOs

Hi all. I absolutely love this B1300 I’ve bought. I think of it as a capable computer with excellent Wi-Fi. I was hoping to do some dev using it. I saw this in a GL-iNet document:

And the same document contains a picture which labels some of the unpopulated headers but not two banks. Is one of the unlabelled banks the 4 GPIO pins?

For reference, the internals

Anyone with any knowledge on this?

I didn’t see 4GPIOs except for the USB pins.