I don't think that functionality was in Genesys version 7.52.
Since I don't have that version installed, I can't be certain. Select your layout and click the File / Import menu. That's where you would see "Gerber File...", if the feature is available.
Since I don't have that version installed, I can't be certain. Select your layout and click the File / Import menu. That's where you would see "Gerber File...", if the feature is available.