To print one photo using the Photo tab within Printer Pro app, follow these steps:
Note: To give Printer Pro access to your Photos: go to Settings > tap Privacy > select Photos > turn On the Printer Pro toggle.
To print multiple images from the Photos application, follow these steps:
If you cannot find your printer model or want to set the paper orientation or size, you can tap More Options button. The application will be automatically closed the Photos app and Printer Pro will be launched. The file will be opened in the Documents tab. To configure print options, tap Print > Print Options > Print.