(Sorry mijn Nederlands is niet zo goed!) Plug directly from PON into SFP+? What cable do I need?

Hello - Sorry, mijn Nederlands is niet goed. I hope it is ok to ask this in English. 

I have a my own router with SFP+ (running Opnsense). I just got 4Gbps KPN fiber.  The copper RJ45 cable from the media-converter from the KPN wall socket is currently plugged into a Copper 10G SFP+ RJ45 in my router. However, this is running crazy hot (>90 deg C)!

Can bypass the media converter and plug the PON connector directly with a fiber cable into a fiber SFP+ in my router?  What cable do I need?  (I use SFP+ modules with LC connectors in my home network but happy to buy a multi-mode SC SFP+ if this is needed).

Everything is working find at the moment.

Thank you in advance!