Open the photo you want to download
Click the three-dot menu or download icon
Select Download
Choose a save location if prompted
Open the Files app to find the downloaded photo
If the photo is in Google Photos, open the photo and click Download
If the photo is in Gmail, open the attachment and click Download
If the photo is on a website, right-click the image and select Save image as
If the photo is in a messaging app, open the image and use the download option
Check the Downloads folder in Files if you cannot find the photo