New ISP/SIM needs activation by dialing a number but doing this on my cellphone links the SIM to the cellphone not to the fresh IMEI of the Mudi PRIVACY Router (we don't want to defeat the purpose 
)
How do I make a phone call from the Mudi router using web interface or shell? The ISP doesn't require any keypress or menu - just a very short init call.
Is it possible?
I tried sending ATD"8282" to ttyUSB2 and it says "Success" (top HTML) and in terminal: "OK" but nothing seems to happen.
It's not possible, please insert the SIM into a phone before.
USSD commands are not possible either - so far.
@bruce Maybe these "activation" steps could be something for R&D to look into?
The concern about the "privacy" by linking a phone is a real thing - even if it might be rare.
Sorry about unavailable to support this 
It requires the router support phone feature, which means the VoLTE/VoNR fully feature to create the calling connection, even it just the short call.
(The Internet and voice in the modem are the different channel.)
May can try to active the SIM in the phone, and clone the phone IMEI to the Mudi.
Maybe sending a SMS is a way to activate as well?
Totally opposite of what the OP wanted 
The idea is not to associate your own phone IMEI with the Mudi SIM card.
@john718 You can get a cheap 3G keypad feature phone which are sold everywhere
for a price of a lunch. A good thing to have for emergency backup as well.
This only happens with your country, I don't remember being anywhere that required me to actually call some number to activate a SIM. Sometimes you have to load it via USSD but thats about it, and usually I did it when I purchased the SIM in a phone shop (since they never ask ID).
Anyway USSD is supported by the modem itself, you will have to SSH to the Mudi and use this thread as a reference: USSD for Mudi GL-E750 - #5 by Bpz1970
You need to put the modem in GSM mode first,
AT+CSCS="GSM"
sorry
It cannot be sent currently in the UI.
You can only SSH into the router terminal for USSD sending
This feature will be considered for future releases
The firmware version will be upgraded continuously
Can you elaborate?
thank you
sorry
We did not develop the modem firmware
It was developed by quectel
Exactly
By the way do you have a specification sheet with AT commands (and modem specific syntax) for this modem? Thanks a lot
I often use https://m2msupport.net/m2msupport/atcpin-enter-pin/ (you can switch the commands by the dropdown) and AT Commands Guide for GSM | emnify Developer Blog