Hi 1nf0t3ch,
Welcome to Affinity Forums
Since this is an afmacro file (without an "S" at the end) - which contains the steps of a single macro - you have to import it from the Macro panel (not the Library which is used to import a set of macros - an .afmacros file). So go to menu View ▸ Studio ▸ Macro to enable this panel, click the Import icon on the top right of the panel and select the .afmacro file. To add it to the Library for later re-use click the second icon on the group on the right on the Macro panel.
