That would largely depend on the make and model of the sat nav. Unfortunately I am not psychic (despite any assertions to the contrary on the part of my children) so I can't even begin to guess.
One would suggest there may be a connector marked "AV In" or "Video In"
It may be expedient to read the manual.
If you don't have a manual, reputable manufacturers usually make their documentation available online.
Acp, August 2017
