Variables sequential numbering to PSD files

https://forums.adobe.com/people/Nick+Walker  wrote Mac OS X, Photoshop CC latest version. I have a folder of 44 images and would like to automate adding a number to each photo. My attempts using variables isn't working - Photoshop will only add a number to the image open in Photoshop and not the other 43 images in the same folder. All images and text document are in the same folder. I have tried using a plain text document with only the number required to be added to each image. Also a text file with the number of each image, tab ot comma, and number required to be added to each photo - reversed order also. I have tried opening all of the photos in Photoshop, instead of only having the first image with a text layer (no 1) open I can change the number on the first image open in Photoshop but nothing happens to the remaining 43 images. Is there a way to instruct Photoshop to find all 44 images and apply a sequential number please?

Renaming is not a task for the editor, unless you use the 'File >> Process multiple files... batch process which creates renamed copies.

It's a feature of the organizer. Do you use it?

If so, the menu File >> rename lets you rename sequentially your highlighted files by a common starting text string plus the sequential number.

You also can use the 'Export as new file' process to rename sequentially.

Typically, you can use albums, set the custom sort order to be sure the sequence will be what you want, and export renamed copies to be used by another software.