Hi
If you mean to create shade/canopy for the pagoda?
Then I think the cheapest option is IKEA in Murcia, they do a plane white sheet canopy’s which comes with required fixings (lanyard, rings and springs). You have to buy the wall fixing yourself usually hooks to clip it onto, from DIY shop.
They sell them for about 20 Euros. They come in rectangular and sail shapes just select best option for you. They are also washable.
Other options are proper fitted canopy’s which are being offered by a number of companies in different designs, but are quite expensive although look very good.
Hope this helps