To convert an image to a PDF on an iPhone in 2024, follow these steps using the built-in functionality of your iPhone:

  1. Open the Photos app and locate the image(s) you wish to convert.
  2. Select the image(s) by tapping each one until a blue checkmark appears in the corner.
  3. Tap the Share icon (square with an arrow pointing upward).
  4. Scroll down and select Print.
  5. On the Print Options screen, tap the Share icon located in the upper right corner.
  6. Choose Save to Files from the sharing options.
  7. Navigate to the folder on your iPhone where you'd like to save the PDF.
  8. Tap Photo at the bottom to change the file name if needed.
  9. Tap Save at the upper-right corner of the screen.

To find the saved PDF file:

  1. Open the Files app.
  2. Navigate to the folder where you saved the PDF.
  3. Tap the icon for the PDF file to review or share it.

Additionally, you can use a third-party app like Photo To PDF Converter, which is available on the App Store. This app allows you to convert photos to PDFs and offers various preferences for page margins, orientation, and size.

Please note that it's not possible to import PDF files into the Photos Library on recent system versions, as Photos is designed to support image formats created by digital cameras, not graphics files like PDFs.