I'm not sure how this is supposed to work - I come from LaTeX, and for books and magazines, some basic enumeration (+naming / caption) and list of figures with captions should be possible without much effort in affinity publisher, even though is should also be possible to change the design as required.
For a simple LaTeX-example, see https://tex.stackexchange.com/questions/240022/put-a-caption-under-a-drawn-picture
I haven't seen any good examples or best practice guides for affinity publisher yet to achieve this (maybe including/automatically creating table-, picture-/figure-indexes etc. with changeable default settings).