Trouble with installing Easy tether on GL-AR150

I am very new to this and don’t have much knowledge with routers/modems. I am following the steps I found here EasyTether - GL.iNet Docs however, when I try to do step 3.iv which is

iv. Install the driver by typing the following command and then hit enter:

opkg install /tmp/filename.ipk

I get the following error:

Packages for easytether-usb-openssl found, but incompatible with the architectures configured

You used the wrong version. Pls follow docs version 3 EasyTether - GL.iNet Docs

Depends on your firmware version, you should download different ipk.

For example,

For firmware v3.201 and newer please use OpenWrt 19.07

For firmware v3.105 and earlier please use OpenWrt 18.06