I purchased the PRO version but there is nowhere a printing option. I have already uninstalled all versions and installed the Pro version again, but still no printing possibility found.
The software never allowed printing. Based on its description, you can export the created content to an image and then use that image and print it. By default and based on its description, you can export images with content to a JPG file having A4-paper-size format.
You can check for additional details about Ensemble Composer using the following link: https://play.google.com/store/apps/details?id=com.lotuz.musiccomposerpro