Are they in the same Symbol?
2 quick ways I think you could do this
Have the polygon layer with a marker layer with a centroid placement. The text in the point could be static or driven by an attribute connection. Then publish to Online making sure to keep the compatible symbol option unchecked.
RussRoberts_0-1713368180789.png
Quick example
https://www.arcgis.com/apps/mapviewer/index.html?webmap=25c5785b63db4b809e43b8597509e365
RussRoberts_1-1713368275145.png
RussRoberts_2-1713368305945.png
Or publish the map with 2 layers. One with a centroid layer and another with a polygon footprint layer. Then set the scale ranges to how you would want them defined.