Simple wall hooks, large surface area for better adhesion.
Three types, triple, double, single.
I used clear adhesive tape to attach it to a tile wall.
Search for nano tape on AliExpress.
AliExpress:
https://www.aliexpress.com/item/1005005844953456.html
Amazon:
https://www.amazon.com/ZMUAXUAN-Mounting-Removable-Adhesive-Waterproof/dp/B095WWRFXF