Saving WMS layers in ArcGIS Pro so that they are accessible offline

How do I save WMS data, specifically WMS layers, so that they may be accessible online?

I am using these two databases:

• one with layers containing map information:

( https://ags.cga.harvard.edu/arcgis/services/darmc/roman/MapServer/WMSServer? )

• one with layers containing topography:

https://image.discomap.eea.europa.eu/arcgis/services/Elevation/EUElev_DEM_V11/MapServer/WmsServer?

Initially, I tried to access these datasets by downloading them – but ArcGIS Pro wouldn’t allow me to show these, so I wasn’t sure what was going on. I’m a first-time student researcher here and I’ve never used anything GIS related before.