Ah.
That dang thing I have been looking for at least a week at home!
We had several of them and I can't find any!

So I use the kettle for French press coffee from Ikea for tea. It works pretty well.
https://www.ikea.com/cz/cs/p/upphetta-konvice-na-caj-kavu-sklo-nerezavejici-ocel-kremova-80583739/