How to update a child element in firebase?

Question

JavaScript

I use firebase 9 firebase 9 Realtime Database
I want to update this element, but how can I get to it if I don't know the path to it in advance, or does it need to change the key to a unique one? or add a key property, but how then to find it by this property?
I want to know if the search method in the database without specifying the entire chain of parents by property or by key? and maybe there is another search method, then what is it too? and how to use it?