It is available either through the Garmin Connect phone app (typically in device settings » User Profile » Hert Rate & Power Zones » Power » Cycling » FTP, though the exact path may vary slightly from model to model), or directly on the device.
I own neither Edge 1040 nor Fenix 7, so cannot confirm anything, but if you do not see it there, then it indeed looks like that. Personally I do not remember I ever had it in GC Web.
