How can I add the live data from this website to ArcGIS Enterprise online?

[CharlotteWhite]

Here is the link to the data I'm trying to add: https://maps.waterdata.usgs.gov/mapper/wateralert/

I've tried to add it under several types of links from the "Add Layer from Web" option, but an error comes up every time. I already have the USGS river gauges but am in need of the rain gauges. The only pre-existing data in ArcGIS is rain gauges for the state of Hawaii. Any ideas? TIA!