Medium Transport; Low Wing; 2 Turbojet Eng
Situational Awareness; Communication Breakdown; Time Pressure
Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented; Flight Crew FLC Overrode Automation
Chart Or Publication; Human Factors
On the visual to Runway 20; just passed the final approach fixed; the FO (First Officer) was descending to catch the glide slope indication for the ILS 20 which was being used as a backup to the visual approach. At 1800 ft MSL he disconnected the autopilot and stopped our descent. He stated we looked low compared to what the glide slope indicated. At this moment ATC advised us they received an altitude low warning on our aircraft. We acknowledged and corrected the flight path to continue the approach. The Captain advised ATC [that] the glide slope was giving the wrong information. ATC responded saying the ILS was out of service. At this point we realized the NOTAM for the ILS was still active. We briefed the NOTAM was inactive and would not affect the approach.The main cause of this event was a misinterpretation of the NOTAM that stated the ILS was out of service. Contributing factors included: Quickly looking at the NOTAMS during descent; having the EFB (Electronic Flight Bag) on a low brightness setting and having the release in a non-inverted setting.   This event can be prevented by reading/ understanding the NOTAMs completely and therefore not rely on a system that is out of service.
Air carrier Captain reported receiving a low altitude alert from Tower on final approach.