If your camera shows the screen below and it doesn't change, it means that the connection with your phone was not successful .Look at your phone if there is a message that explains the error. If so, correct and reconnect.
Here's what to do:
1) Select Disconnect, exit and click OK to confirm the disconnection.
2) Close and open the device again.
3) Check if you have the right settings for Exposio in your camera:
SL2 / EOS 200D camera settings for Exposio
SL3 / EOS 250D camera settings for Exposio
4) Try again the connection steps:
First steps with the SL2 / EOS 200D Pro Kit - WiFi (iOS)