Rubber Gasket in Water Tank

Does anyone know what this rubber gasket is, I found it in my water tank after cleaning and doing a descale. I’m guessing it somehow attaches to the outflow of the tank, but I don’t see how.

Found some more parts in my sink. Looks like a sort of valve or something. Anyone have instructions or a diagram on how it’s supposed to attach? Ugh, I’ve had nothing but trouble with this oven since i bought it.

I would contact support and ask them. I have not seen any post similar to this.