When you select Patient Arrival option for the All Flowsheets Begin at setting, you can only use non-fixed templates and that is why the setting is grayed out and templates are not shown to you:
NOTE: In this case, if you have an integrated EMR, when you try to push the patient over to Smart Flow, your EMR cannot recognize the fixed template so can't send the patient. Find more detail on how to use the templates in this case HERE.
We hope you found this information useful!