Yes, my ask was about a feature to create image maps. From a Google search, I thought this feature already existed (see https://affinity.help/publisher/en-US.lproj/pages/Advanced/hyperlinks.html) , but I couldn't find the menus that these instructions refer to.
In Adobe Illustrator, it is possible to embed links in image maps, and it does solve some problems when passing on images for social media to clients and when posting yourself, as the embedded links make the image into a button, effectively. I find this very useful. It can also be done in Canva, even in the free version.
As this can be done for free on Canva, I will keep adding hyperlinks there, but I thought I'd ask Serif, as this is a functionality I appreciate and would like to be able to use in Affinity.
Ta to everyone who took the time and effort to answer. Much appreciated, @Walt.farrell, @fde101