When attempting to build a custom Flow, I have very few (5 total) Dynamic Content options for adding variables to my Flow. When I build something from a template, I have far more options for defining Dynamic Content available to me. What do I need to do to make these options available in a custom Flow? Do I need to build them with code? Do I need to import them somehow? Do I need to upgrade to a better version? Do I need to contact my IT department to see if they need to activate them on their end before they're available to me?