Strong shadows can ruin a good image, and mostly because they fall across the focal point. Here’s one way (among many others!) to reduce their overall impact.
Not only do we need to keep a copy of the original layer, but we to apply a blend mode too. Drag the Background layer on to the Create New layer button to create a duplicate version.
Set the duplicate layer’s blend mode to Screen. This will lighten up the whole image, reducing the strength of the shadows.
Add a mask to the duplicate layer and then press Crtl/Cmd+I to change it from a white mask to black.
Select the Eraser tool and set your Foreground Color to Black. Paint over the shadows to remove the mask to reveal the lighter areas underneath. Keep brush Hardness to 0% and the closer you get to the edges of the subject, decrease the size of the brush tip.