Label feature not showing in tool panel

[UKAlex]

Hello, I'm new to ArcGIS Online so sorry if this is a stupid question. 

I'm putting together a map but the Label Features icon isn't available in the right hand panel of Map Viewer, its just not there, so I I can't work out how to label anything.

Any pointers appreciated

Alex 

 

[UKAlex]

Update - Selecting a line feature brings up the label symbol, but its not there for point features - why not?

[RussRoberts]

We hide the label option on multipoint layers. Can you check if the layer is point or multipoint geometry?