If you have been through all yoir BIOS screens and cannot find that switch, don't worry maybe age of your machine or its BIOS preceed that.
Can I ask what is your make/model of machine?
Has its BIOS been updated?
I have read here on the forum, that nvme drives have a reputation of being difficult when installing linux distro's. One user @seanhinkley here on the forum, suggested selecting RAID not AHCI if you have a nvme drive, which yours looks to be, as the labels on your Gparted partitions seem to indicate that. Zorin OS pro 16.3 installer NVME disk not detected. - #11 by seanhinkley
My queston asked if you were running Gparted using "Try Zorin" mode off the USB or running Zorin and Gparted from the nvme drive. If from the nvme drive then I think that drive and partitions would expected to be shown as mounted/locked like your screenshot.
As you are using EFI then that EFI partition and its size are expected. The ZorinOS partition is then the ext4 formatted partition. Are you able to click the ext4 partition to expand and show partitions within that.
Are you able to boot ZorinOS Pro from your internal nvme drive or does it fail?
Note. As you have purchased Pro, you are entitled to request support from the devs, but do bear in mind they are only 2 people, so you would need to be patient with them.