ORBI75

I think I get it now.  This appears to be part of a program by Pacific Gas & Electric, Southern California Edison, and San Diego Gas & Electric. The customer installs 'smart devices' in the house to control appliances that use electricity and allows the electric company to turn them on and off during specific times of the day.   (See footnote at the bottom of the page: https://www.ohmconnect.com )

Most refrigerators connect to an electrical outlet which is physically behind the refrigerator.  If the metal refrigerator is blocking WiFi signals from the front and the lath & plaster walls are blocking WiFi signals from the back, it may be a challenge to get any WiFi device connected. This has nothing to do with the brand or model of WiFi system. It is radio physics.  There are three things that might work:

• Connect the Ohm Plug to the 'app' with it plugged into a different electrical outlet where it has a clear view of the smartphone and gets a strong WiFi signal.  After the plug has been configured and is known to function correctly, then move it to the electrical outlet behind the refrigerator.  The plug receives and transmits almost no data at all (just "turn on", or "turn off").  Maybe it will get enough of a WiFi signal to do that after it has been set up with the app.
• Plug an extension cord into the wall outlet, the Ohm Plug into the extension cord, and the refrigerator into the Ohm Plug.  Use tape or something to place the Ohm Plug somewhere that is not blocked by the refrigerator (on top? to the side?)
• Get an inexpensive WiFi extender that can be placed where it gets a good WiFi signal and can be 'seen' by the Ohm Plug.  A TP-Link N300, for example, is $16 on Amazon.  WiFi extenders are used quite often for situations where a device that never moves doesn't get a strong enough WiFi signal. (garage door openers, sprinkler controllers, pool controllers, security cameras, etc.)