I wanted to set up an ESP32-CAM at a remote location which connects to internet via 3G Alcatel Y580 SIM card mobile router:
https://manualzz.com/doc/2426214/alcatel-one-touch-y580
So the setup looks like this (or at least this is how I imagine it):
ESP32-CAM -> 3G mobile router -> internet ->xxx.ddns.net -> home WiFi router -> PC -> Blynk local server
Before attempting 3G connection I tested the sketch on my local WiFi network where I have a Blynk server running on my PC. I used the code from this tutorial (bottom).
https://www.viralsciencecreativity.com/post/esp32-cam-blynk-multiple-camera-surveillance
Everything worked as described (I have one camera only).
After that I changed the ssid and pass to the 3G router ones and attempted connection with my Blynk server.
Before that I signed up with No-Ip.com and got a DDNS host name and opened ports to my local WiFi router.
Then got one of my NodeMCU projects running via 3G without problems however I have the following problem with the camera: it looks like it connects to the Blynk server because when I press the button camera LED flashes and Blynk displays the local to the 3G router camera IP address but it doesn't take pictures (camera was tested thoroughly and works).
Considering my limited knowledge of networks please advise what could be the problem.
I did long searches and couldn't find anything that's close to that situation. Most of the time USB dongles and advanced routers are mentioned but nothing like this. I don't believe I'm the first one to attempt such connection so maybe you can help me find a solution.