I followed the docs here: EasyTether - GL.iNet Docs and EasyTether is working for me via my Pixel 3a. (Thanks Alfie for the extra help!)
But in interfaces, it shows up as Offline show I can’t use it with mwan3. It also doesn’t show up in the main Admin Panel.
What do I need to do to make it show as Online?
To partially answer my own question, EasyTether does not support ICMP(PING) which is why the interface is shown as Offline. In, mwan3, I switched it to use httping with hostname google.com which does bring it Online initially but then a few seconds later it goes Offline again.
12: tap-easytether: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UNKNOWN group default qlen 1000
link/ether 02:00:54:74:68:72 brd ff:ff:ff:ff:ff:ff
inet 192.168.117.2/24 brd 192.168.117.255 scope global tap-easytether
valid_lft forever preferred_lft forever
httping in mwan3 does has bugs and need to fix.