This is a weblayer (feature layer) item page on enterprise portal
https://gis1.victorvilleca.gov/portal/home/item.html?id=4f1531b032f547f08c6fb87fe09f6349#overview
Option 1. click Service URL,
Option 2. click Setting
Option 3. scroll down at bottom
Open the arcgis rest api end point page
https://gis1.victorvilleca.gov/arcgis/rest/services/COVInternal/GISPROD_FireServiceOperations/MapServer/64