Open the photo on your device
Select the Print option
Choose Save as PDF or Print to PDF
Adjust page settings if needed
Save the file as a PDF
On iPhone, open the photo in Photos, tap Share, tap Print, zoom in on the preview, tap Share again, then choose Save to Files
On Android, open the photo, tap Share or Print, then choose Save as PDF
On Windows, open the photo, press Ctrl+P, select Microsoft Print to PDF, then save
On Mac, open the photo, press Command+P, click PDF, then choose Save as PDF