The only way to produce PDF documents from .afdesign files would be to use the original software where they were created, in this case of Affinity Designer. We haven't found information about any other software that would be capable of this afdesign to pdf conversion.
Convert Serif Affinity Designer document to Adobe Portable document format.
We have found 2 software records in our database eligible for .afdesign to .pdf file format conversion.
Microsoft Windows software - convert afdesign to pdf on Windows
Vector graphic design software
Convert from afdesign file format
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned afdesign to pdf. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
Apple macOS / Mac OS X software - convert afdesign to pdf on OS X
Professional graphic design software for the Mac