Compiling Openwrt Github Package to single ipk

[juppin]

Update to 19.07.0 and you can install your package from the official repo.

OpenWrt 19.07.0 first stable release

Hi, The OpenWrt community is proud to announce the first stable release of the OpenWrt 19.07 stable version series. It incorporates 3954 commits since the previous release 18.06.0 and 85 commits since the previous release candidate 19.07.0-rc2. An upgrade from OpenWrt 18.06 to OpenWrt 19.07 is supported in many cases with the help of the sysupgrade utility which will also attempt to preserve the configuration. A configuration backup is advised nonetheless when upgrading to OpenWrt 19.07. …

http://downloads.openwrt.org/releases/19.07.0/targets/ramips/mt7621/openwrt-19.07.0-ramips-mt7621-xiaomi_mir3g-squashfs-sysupgrade.bin

You can do it like the following from a ssh shell:

cd /tmp
wget http://downloads.openwrt.org/releases/19.07.0/targets/ramips/mt7621/openwrt-19.07.0-ramips-mt7621-xiaomi_mir3g-squashfs-sysupgrade.bin
sysupgrade openwrt-19.07.0-ramips-mt7621-xiaomi_mir3g-squashfs-sysupgrade.bin

I´m assuming you are using the first version of MiR3G and not MiR3GV2 as the new version isn´t supported on 18.06.