Board Thread:Support Requests - Getting Technical/@comment-32049085-20200429223506/@comment-9605025-20200430171519

First off, it isn't a "data source" tag. It is a "data" tag with an attribute called "source". Second, you cannot place a data tag within a header tag.

May I ask why you want the editor to set the header text? Usually, infoboxes are used to display data in a standardized format. So having a header that changes with each use is sort of against this general intention.

You can allow the editor to change the text by using the normal template parameter syntax. However, if you do this, I don't know if the template parameter will show in the fields form of the visual editor. Another alternative would be to use a title tag instead.