I've bought a Snooze Shade, highly reviewed and have a UV rating too. https://www.snoozeshade.com/
Hi. I had this one https://amzn.eu/d/2oaAUDY Its mesh so baby can see through it even if you cover the entire pram..But cool en comfy inside letting through some light, so not dark when completely covered.
Snooze shade
So far I peg a muslin to the hood. I can't find a parasol I like that's rated and I really don't want a snooze shade because I just simply want the sun out of her eyes rather than for when she's sleeping as she's mostly awake in the pram. I just pull the muslin over the one side slightly when she sun is in her eyes.
I bought one from smyths for 14.99 it's an open sunshade so it doesn't cover the whole pram. It's adjustable and fits any type of pram. Easy to take on and off when needed and it had a zip on the top to check on baby. https://www.smythstoys.com/uk/en-gb/baby/pushchairs-and-strollers/pushchair-accessories-and-toys/babylo-solar-upf-50-stroller-sun-shade/p/169694