TOPIC: DT Register - Details Article or Menu Item

I am considering re-purchasing DT Register for our new website.

However, I need to know if it is possible in the newest version to assign a MENU ITEM (instead of an article) to the EVENT DETAILS ARTICLE?

Currently (in version 3.1.9), it only allows me to select a general joomla article. However, I am using "SP PageBuilder" now, so there are no longer any regular joomla articles on my site. All of the pages I created using "SP PageBuilder" are not listed as an option when trying to select the "EVENT DETAILS ARTICLE"... DT Register does not see them as valid articles for selection.

Therefore, I really need the ability to select a MENU ITEM instead of an article for details. I have already tried inserting the menu item ID in the "DETAILS LINK ITEMID OVERRIDE" field, but this is not working either.

No, the details article is still the selection of a content article. You can consider using the event description, which shows on the list view, and create a link there to your event information. You can use that instead of the built-in details article feature. You could then manually put the EventLink plugin syntax into your event pages to manually place the register button on those pages. Simply put:

...into any page. Obviously, replace "event_id" with the ID number of your event.