Affinity Photo is the only software that can work with .afphoto files, which means the only way how to export these files to other format is to use the software. If you do not have access to the software, you have to either find someone who does (to make the export for you) or try the trail version of the software. But except for that, there is really no alternative how to achieve afphoto to jpeg conversion.
Updated: May 9, 2023