The "CIDFont+F1" (F1 to F7) fonts do not actually exist as downloadable font files.
What is a CID Font?
To understand why you can’t simply download "CID Font F1," you have to understand the technology. CID stands for Character Identifier.
If you're looking for a free download of the CID Font F series, you're in luck! There are several websites that offer these fonts for free download, including:
2. Using mutool info (from MuPDF – free)