The Settings.h tab of the Edgent example sketch is where you specify which pins are used for the Blynk LED and button that will clear the stored WiFi credentials.
You may choose to use the Wemos’s onboard LED, and connect a physical momentary switch between another pin (Maybe GPIO0) and GND.
You provision the device via the app (when the LED is flashing) then iof you wnat to clear the stored credentials you press the button for 10 seconds. You can then re-provision the device via the app with new credentials.
More info here…
Pete.