Diagnosis
The activation process is hung up. This usually happens because of a hiccup during the initial WiFi transfer from your phone to the camera, or the camera can't phone home to SimpliSafe's servers to finalize setup.
How to Fix It
You need to do a hard reset and start over. 1) Unplug the camera. 2) Find the tiny pinhole reset button on the bottom of the camera. 3) Use a paperclip to press and hold that button down. 4) While holding it, plug the power back in. 5) Keep holding the button for another 15 seconds after it's powered. You'll hear a voice prompt. Then let go. This wipes its setup completely. Now, delete the camera from your SimpliSafe app entirely. Finally, add it again as a brand new device and follow the in-app prompts carefully.
If That Didn't Work
The issue could be on SimpliSafe's end. Before trying setup again, check their system status page online to see if there's a known activation outage. If everything looks green, try the setup again but make sure your phone is connected to your 2.4 GHz WiFi network (the camera doesn't work with 5 GHz for setup) and that you're standing right next to the camera with Bluetooth enabled on your phone.
Heads Up
During setup, when it asks you to scan the QR code, make sure you're in good light and hold steady. If it fails a few times, you can manually type in the serial number instead. That often bypasses a flaky scan.