[HELP] Restore the stock gallery app

Hi,

I removed/uninstalled the stock gallery app. Even though I have google photo installed, I got an error message when I try to access gallery by clicking the gallery icon in the samsung stock camera app. I also could not set the wallpaper for the lock screen, as when I click the gallery icon in the setting screen, it gave me similar error message saying "app not installed". Could someone tell me how I could restore the stock gallery app, or change the default app to google photo (preferred option)? Thanks in advance for your help!!