Short tip: Shelly Plug does not find newer firmware

The Shelly Plug WLAN socket adapters from the Bulgarian manufacturer Allterco are very popular. They are inexpensive and - unlike other alternatives - also allow switching without cloud constraints via their own MQTT broker. However, some devices come with severely outdated firmware, for which the search for updates fails. Manual searching for new firmware versions does not help here either:

Fortunately, there is a firmware archive on the Internet that generates update links for specific versions. All you have to do is enter the IP address of the device, select the device type and the desired firmware version.

In my case the device type is SHPLG-S (Shelly Plug S), the latest firmware was v1.11.7:

It is sufficient to copy the link and open it. Then the device will download and install the firmware.