Hi @Masiti_Imrona - Please be very very careful with editing this as this code handles all of the networking functionality of the device. I would keep a backup on your PC to be sure you can restore it if there’s an issue.
The folder /var/www/luci2/view contains Javascript files that are used to generate the menus. Here’s what it looks like for wireless
You will want to change the string in the quotes after caption:
caption: L.tr('2.4G WiFi device')
to
caption: L.tr('Perangkat WiFi 2.4G')
And you can see it changed
Hope that helps