It's great that you want to make your own cover photos using the cover maker.
Making covers with this cover maker is really easy. Just 3 simple steps.
1. Add Your Photos
2. Move, Resize as you like and add texts.
3. Click the Apply button to create and upload to facebook.
However, you must be logged into facebook with the CoverBash app and granted it publish permission to apply the cover on your facebook profile or it will not be able to upload the cover when you click apply button.