When you first install SeriousMD and use the camera or photo library, it will ask you to allow their use.
If you happen to disallow it, you'll see an error similar to this (image below)
Here's what you need to do:
Go to your iOS device's "Settings"
Scroll down until you see the SeriousMD icon called "Doctors"
Make sure to allow Photos/Camera/Notifications/Keychain
If you happen to see something like the image below where the camera and photo library options are missing, please contact the support team and report the bug.