Ham Radio Deluxe shows error 403 when Club Log rejects an upload. This happens if the email address, password and callsign are not correct. Error 403 means access denied.

This is caused by a missing setting for your callsign in HRD.

Go to Tools > configure > My Station
Look at what's in the Operator Callsign field.

If your call is not there or it shows your name, enter your callsign.