adding iptc keywords with a shell script and exiftools Need help

I have a automator action that renames a group of photos and then I what it to ask for keywords and possible other metadata. But for now just keywords.

I can ask for text to get keywords and set that text as a variable, but I’m not sure how the enter that into a shell script so the exiftools command will use the text string from the variable as the keywords.

Ok here is the cod I think I should be using minus the location where the keywords go after the “:”

Anyone know how to do this?