I have a large garden shed that needs a roof vent. I purchased a bastion roof vent https://www.bunnings.com.au/bastion-300mm-aluminium-mill-roof-vent_p0810899 and found there is no guidance on installation method in the box, their website - anywhere.
The garden shed 4m x 4m and too light a construction to get onto the roof to complete the install. I can see other brands suggest installing under the ridge capping, but I can see its too risky because of the light roof construction. The pitch is much less than shown in the di.agram below

What is the recommended method?
regarding instruction, I was surprised not to find something - I'd understand if I purchased it on Temu, not Bunnnings.