Below are the steps I went through:
Generate the certificate request:
Upload to the Apple Dev Portal, download the certificate.
Select it in the Xamarin Project options:
Tried to build, when getting to a codesigning it asks permission (is a name being "" correct?)
However same frustrating error:
"Error: No installed provisioning profiles match the installed iOS code signing keys"
I see in a csproj I can also specify code signing attributes - should I try to set these manually? Where can I find all the keys of a signing profile / certificate to do so?