total novice to encryption

I have a situation where the sender of a file requires PGP/GPG encryption - but I need 3 people to be able to decrypt the file.

Sending multiple keys to the file author is not really viable.

If I create and export a private key, and then instal it on the 3 users PC’s will that allow them all to be able to open the file encrypted with the single public key?

Many Thanks for any advice.