Question about slide-switch package for TL-MR3020

hello everyone, i am a new user of openWRT...i have just installed openWRT into my TL-MR3020 last night.
the only thing i am unable to figure out is how to set the slide switch to set the interface between 3g, WISP, and AP mode using slide-switch package made by jefferyto...can anybody here guide me on how to set it up?? i have seen a tutorial from openWRT but it is still hard for me to understand...and the example is not clear.....any help from here is really appreciated

anybody here can answer my question?

The WPS button is located at the top (illuminated by the WPS LED) and can be easily pressed with a finger. The sliding switch is located at the side and has three positions: 3G, WISP, AP.
Sample scripts to read the sliding switch: on boot, on switch change, to change network configurations

From https://oldwiki.archive.openwrt.org/toh/tp-link/tl-mr3020

New URL: https://openwrt.org/toh/tp-link/tl-mr3020

The old page is for archival purposes only and does not receive updates any more.

grafik