A small question

Hi My Brothers,
I have a small question. I am making an app where you can collect points and withdraw them.
I know how to build a point system but I doubt how to subtract points after withdrawal.
anyone can help me

well thank you for your time
:handshake: :handshake: :handshake: :handshake: :handshake: :handshake: :handshake:

Lets suppose you are storing users points in firebase

So first you will get that point using Firebase GetValue block then store that value in variable

Now on withdraw button click Use firebase StoreValue block and In tag, write the same tag which is used for storing previous value and In Value, use math subtract block (Variable - withdraw value)