Palram Hybrid Greenhouse on Patio- fixing to concrete and other issues

Hi , has anyone experience of fixing this to the ground with screws ? I have just opened this up  and planned to fix tomorrow but cannot find the screws to anchor as i wanted to measure and go buy the correct masonry drill bit . Palram are not answering their phones ...however i have managed to work out that i need 8mm diam screws but not sure how long and also when line up this black plastic connector then the screw holes doe not all line up - anyone else had that problem ?