Welcome to FT. I have not done it personally. From reading various posts, you might be offered to change to Global Entry when you first log into GOES website renewing your NEXUS. If you were not offered to change to Global Entry, you then have to apply for Global Entry which is a different program and pay a $100 fee.
If you have been approved conditionally for NEXUS renewal without an interview, if I were you, I would renew NEXUS. If an interview is required, then apply for Global Entry.