@Sara
As @Greg_F pointed out, this can only be resolved with external 3rd-party services.
There are dozens of different services out there that provide this functionality, such as Documint, Docupilot, PDF Generator API, PandaDoc, pdfFiller, PlumSail Documents, Formstack Documents, DocSpring, PDFMonkey, Anvil, PDF.co, and many more. You could even use plain old fashioned Google Docs or Microsoft Word as well.
All of these would need to be automated in some way. Some of them have native extensions for Airtable. Others would need to be automated by writing your own Javascripts or by turning to a low-code/no-code automation tool like Make.com, which doesn’t require any knowledge of coding. On2Air: Actions can also help with Google Docs and Google Slides.
Note that I do not personally recommend Zapier, because Make.com is more affordable and more powerful and more customizable.