Exactly which ISO file did you download?
That paragraph describes what you would see if you ran the netinst.iso
WITHOUT an active network connection.
IOW, for whatever reason, the installer does not have access to a
repository.
It's the debian-10.2.0-amd64-netinst.iso
I did ran the .iso without an active network connection, because it refused to connect to my wifi. It asked for the ESSID (?), which I assumed is the same as SSID, so I typed in the SSID and the password, but it just would not connect.
I'll try again. Thank you