Affinity Photo is very easy to handle.Interface is almost same to Photoshop.In this Hindi video tutorial you will learn how to open and save images with history,Detail explanation about Export persona.You can export full image or slices in lots of formats like as png,jpeg,tiff,pdf,bmp etc.
First create new document from file-new.Select presets and their respective sizes.You can set width,height,DPI.Once done,click ok.It will crate a new blank document.It is just canvas ,not a layer.
Open another images,copy and paste them as multiple layer.Go to File and check save file with history,it will save your image in Affinity format with history.
Once you are ready to export the finished image, click on the Export tool (Persona) at the top left. The righthand panel now changes to provide Export Options. If you are happy with one of the standard presets, you can simply select it from that popup menu, and click on the Export 1xbutton at the top left to obtain an unscaled JPEG (or whichever image format you selected).
You can export many slices at a time.