If your goal is to hide a text message inside an actual photo file (resulting in an image that looks normal but contains hidden data), you can use the command prompt:

: Right-click your text file (e.g., Ophoto.txt ), select 7-Zip > Add to archive... , and set the archive name to Ophoto.7z . [32]

To package a text file into a 7z archive, you can use standard archival tools or online converters: