Looks like the access is restricted, but the contents are almost similar to the list provided by Anthony earlier - https://www.fortinet.com/content/dam/fortinet/assets/data-sheets/Fortinet_Transceivers.pdf
Again, since the transceiver is not in the list don't mean it won't work, it just means it is not tested by Fortinet. You can test them on your setup and see if it works , it is recommended to use the transceivers tested by Fortinet, which can be found in above document.
- Have you found a solution? Then give your helper a "Kudos" and mark the solution.