Macros are recorded sequences of operations that perform corrective or creative effects. Their purpose is to reduce time spent repeating processes by automating steps instead.
Your Affinity app can import compatible macro files with an .afmacro or .afmacros file extension.
Files with the former extension contain a single macro, while those with the latter extension may contain multiple macros—see After importing.
If the imported add-on is an .afmacro file, its operations are shown on the Macro panel. From there, you can modify or play the macro, or add it to the Library panel for later playback.
If the imported add-on is an .afmacros file, its macros are available in a new category on the Library panel. You may need to scroll down to see them.