Find a Camp and Upgrade the Axe | 6: At An Impasse Walkthrough Tomb Raider Guide

You can use the closest base camp, right by the closed gate, though you may as well backtrack to the previous one (near the bunker).

Open the base camp window, select the newly available Gear tab and unlock Strengthen for the pry axe, which costs 50 points (screenshot) (reward: 100 XP). If you have more Salvage points, you can naturally upgrade the makeshift bow as well.