Air carrier First Officer reported the Captain took the wrong turn after landing at SBP and proceeded onto Taxiway M in apparent violation of procedure. The First Officer stated that there were no NOTAMs or any indication on charts of that taxiway not being allowed for use at the airport.

Narrative

We had a non-eventful landing on Runway 29 and then I transferred the controls to the Captain. The Captain then turned left onto Taxiway M before I had a chance to remind them the terminal was to the right. We decided to just adjust our taxi route and make a position report to continue taxiing up Taxiway M to cross the runway and taxi into the terminal. After making a position report; Airport Operations responded and said we are not supposed to taxi on Taxiway M. There was no indication of this on the charts; notes or in the NOTAMs. If Airport Operations had not said anything we would have had no indication that was not allowed. We continued to the gate with no issue. We briefed the arrival and taxi but the Captain had the wrong idea in their head after landing of where the terminal was. I think another factor was the missing information on the charts and NOTAMs about the inability to use Taxiway M. There was no indication of this information.In the future I will make sure to emphasize the taxiway plan in my briefing better. I will also make sure to speak up more quickly if the Captain does make a wrong turn while taxiing. I also think it would be a good idea to add that information onto the charts or NOTAMs.