Exported PDF files - fonts

I have previously used Adobe InDesign to compile albums of music by placing PDFs exported from Musescore into a standard document. All worked fine.

I decided to move away from InDesign (mainly cost) and have been looking at Publisher 2 from Affinity. Generally good, and pleased.

However, having real problems with PDFs exported from Musescore. If I place several PDFs into the same publisher document to create an album, it throw up errors because the Musescore fonts are not recognised (Edwin, Leland). If I try to correct these using the "fix" feature in Affinity publishing everything is lost.

I'm a bit new to the whole font business - is there any way I can download these fonts so that Musescore PFDs are recognised? I'm a bit surprised you need a font - I thought PDFs were graphics files.

I found use PNG files instead of PDFs, but just wondering if there is any obvious solution to this....

Cheers Stuart