Change Symbology/Labels on Layer that isn't Mine

[CarsonMorton]

I was given the URL to a hosted layer. I've got it added to my online map. I do not want to change any of the data. I just want to change the symbology and labels. I'm not seeing where to make those changes... am I just blind?

[RussRoberts]

What kind of layer is it? If its a map image layer are you looking at the sub layer or a group layer and does it support dynamic rendering? 

[CarsonMorton]

Vector tile.

I don't believe it has any sub layers. clicking on the only thing under "Layers" takes me to a chunk of code.

how do I know if it can support dynamic rendering? (and is that going to be a problem for the field guys using field maps?)