Locate the file within your current job folder (which will not be shown if you haven't done any builds yet). Select the local relative file name without the leading job folder, copy it, then insert as a local file path of a parameter of type media or datatable.
For example, if your project/job name is "myJob", the local files available for selection from this job will be shown as "myJob/myPhoto.jpg" or "myJob/folder-x/myPhoto.jpg".
You need to copy the relative name, namely "myPhoto.jpg" or "folder-x/myPhoto.jpg" and paste it into where it's supposed to be in the Script parameters.
Note: if your project/job files are not shown because you have not done a build yet, do a build. Even if the build fails, the folder for this project/job will be created and you'll be able to place files into it as well as
select them in this selection field.