SPH: The spherical (SPH) determines if you have hypermetropia (+) or myopia (-). The number indicates the strength of the lens you need. A smaller number signifies a milder condition.
CYL: The abbreviation CYL refers to cylinder and indicates the seriousness of astigmatism.
AXS: Axis is a number from 1 to 180. If your doctor has included cylinder power, there will also be an axis value to indicate positioning. Axis is measured in degrees and refers to where the astigmatism is located on the cornea.
ADD: ADD is used in Multifocal Lens (Bifocal, Trifocal and Progressive lens) to indicate the additional magnifying power for the bottom part of the lens.
Since the VR headsets usually have projected focal distances of about 4-6ft (1.2-1.8m) depending on the different VR headset. Bifocal, Progressive and Reading prescriptions will be reduced to the single vision lenses and adjusted for 4-6ft (1.2-1.8m)  focal range.
If you do not have numbers under ADD then you do not need to worry about ADD. If you have numbers under ADD please choose "Extra ADD/Prism" and note your ADD in the order.
Prism: Prism only appears on a low number of prescriptions. It’s used when your doctor feels that compensation for eye alignment is necessary.
If you do not have numbers under Prism then you do not need to worry about Prism. If you have numbers under Prism please choose "Extra ADD/Prism" and note your prism in the order.
Learn more prescription lens terms from this guide: https://zybervr.com/blogs/news/how-to-read-the-prescription-when-buying-vr-lens-inserts