Trying to turn on labels for a dynamic MapServer layer

Question

While I am generally knowledgeable about using the ArcGIS Server REST API to work with dynamic MapServer layers, this is the first time I have tried to turn on labels.

Below is a call for a tile that will display a single green circle.
The value of POITYPE is Visitor Center.
I would like the label ‘Visitor Center’ to appear near the green circle.

Alas, I have been unable to conjure up just the right syntax to make that happen.
What am I missing?

https://mapservices.nps.gov/arcgis/rest/services/NationalDatasets/NPS_Public_POIs/MapServer/export?bbox=-12205302.24789184,4667760.897033789,-12200410.278081588,4665802.198183983&size=1024,410&dpi=96&format=png24&transparent=true&bboxSR=3857&imageSR=3857&dynamicLayers=[{'source':{'type':'mapLayer','mapLayerId':0},'definitionExpression':"upper(POITYPE)='VISITOR+CENTER'",'drawingInfo':{'renderer':{'type':'simple','symbol':{'type':'esriSMS','style':'esriSMSCircle','color':[0,255,0,255],'size':8,'outline':{'color':[0,0,0,255],'width':1.5}}}},'showLabels':true,'labelingInfo':{'labelPlacement':'esriServerPointLabelPlacementAboveRight','labelExpression':[POITYPE],'useCodedValues':false,'symbol':{color:[0,255,255,255],'size':8,'fontFamily':'Arial','fontStyle':'normal','fontWeight':'bold','fontDecoration':'none'}}}]&layers=show:0&f=image

Joseph Elfelt

@mappingsupport

https://mappingsupport.com

JosephElfelt1 · Answer

Someone at GIS stackexchange kindly helped me figure this out.

Here is the finished tile call.

https://mapservices.nps.gov/arcgis/rest/services/NationalDatasets/NPS_Public_POIs/MapServer/export?bbox=-12205302.247891…