Air carrier flight crew reported receiving a ground proximity warning while conducting a visual approach.

Narrative

It was our go-home day and it happened on the last leg which was ZZZ1-ZZZ flight. Flight to ZZZ was delayed because the aircraft was over fueled. By the time we were ready for take off; we already briefed that we are going to land rwy XX at ZZZ. Under calm wind; VMC; we finally took off from ZZZ1 and began our flight to ZZZ. I was the pilot monitoring so I listened the ATIS and figured ZZZ is advertising rwy XY so I launched rwy XY ILS into the system and gave a visual approach brief for rwy XY to the captain. Weather at ZZZ at that time was absolutely clear and calm condition. We also briefed the company page saying that it is recommended to maintain 3000 ft before passing the ridge line however we went down to 2600 and got aural warning. As a pilot monitoring; I should have assisted the captain by reminding her that we should keep 3000 ft until passing the ridge line. Throughout this event; I figured that I'll have to pay more attention to what's written in the company page and reminded myself to become more supportive as a pilot monitoring.