In experience builder, first click on the edit widget to bring up its properties pane, then you should be able to just click the title and type whatever you want here:
Thank you! I was also wondering if there was a way to change the 33 to a different title.
This should get you what you're looking for: https://community.esri.com/t5/arcgis-online-questions/change-default-field-displayed-in-map-viewer-e...
I have had the same issue. Wish it could be done in an easier way.