Hi @AlfredBaldenweck , it is possible. I do not know what the specific documentation is called for htis, ESRI's search pulled this link below though I am not sure it specifically answers your question. If you have a field that the hyperlinks can be put in, whereas the hyperlinks themselves are hosted elsewhere, you can open the hyperlink to the source site with ease. Many organizations do this for specific records and I've seen it done in both Survey123 and for featureclasses in AGOL.
https://www.esri.com/about/newsroom/arcuser/creating-and-using-layer-files-in-arcgis-pro/
Hope this helps get you a good start, that would be my general summary of the process,
God bless,
Jansen Lyons - Records and GIS Section - Public Works - City of Rio Rancho, NM