Where to buy a softcover bike bag

Hey there, first post - flying into TPE tomorrow! I will be taking the train with my road bike in Japan but will be flying into Taiwan first. I heard that Giant carries one, but I am wondering if there are any better options that can fold into a jersey pocket, such as:

Thank you in advance - excited to ride!

I see them online, but can’t find a store that sells them.

https://shopee.tw/韓國NOSBIKE-26寸、27.5寸公路車-登山車-折疊車-單車防塵套-攜車袋-單車袋-車輪套(型號301)-i.8929433.2003297827