After several hours of testing, I confirm the correct operation of the external LTE/5G kit connected via a network card/USB adapter to the previously configured USB port of the router.

@MR.S What a fool I am... And the USB port will turn on and configure itself??? 🫣 I can confirm - after configuring the USB port (in my case, as a backup connection), everything works as it should...

@MR.S Lucky you... Did you change anything in the settings? Because following your lead, I also connected it... and nothing 😞

@Ronczkos My Nokia:

Hello. The USB port on the ER706W can be used to connect a backup internet connection using a USB modem. My question concerns the following option/situation (someone might say, "Why bother asking?...