NET STRONG Universal Repeater 750 firmware download

So i few months ago i got my NET STRONG Universal Repeater 750 and i am wondering where to download firmware for this device, i want this manly for new web dashboard.

I have been searching for a place where i ask shoud ask this question and i think this is it.

I have found this post but when i try to import the .bin file it wont let me import it!

Did you check https://openwrt.org/toh/start?