Add to conversation is not editable.

Holli Kyle, did you do this update in your live theme which I'm watching?

URL of your HC: https://knackops.zendesk.com/hc/en-us 

Error still exists:

Script file:

I think you are doing these update in your local theme instead of live theme.

Oops! It appears I got logged out during making the change however when I made the update and saved it successfully I am still getting the same result. 

Holli Kyle, remove the end_user condition from the script code mentioned below screenshot:

After removing, you code would be:

Currently it's not working for end_users:

Now, let me know your query.

what is your requirement for this button?

Ahhh! That makes sense. I removed the line you mentioned however the add to conversation is still not available. 

We are wanting to use this support center with a partner company of non-agents (end-users) - they need to be able to track their open tickets and add comments on them outside of just their email box.

Thanks again for your help!