Adding support for NuCom WR744G+

Sorry for my bad English.

I would like to know how I can compile an image for this router from a local internet operator, I understand that having the mt7621 there will be no problems.
I have tried to load several images of a DLink (867, 878, 882) due to similarity of characteristics by uart and loading the image in ram the router starts and I have access to LUCI.
I would like to be able to make a custom image for this router.
I pass you the boot log.

I'm going to have to read more examples because I'm too new to understand those steps and to be able to take advantage of the information in the boot log.