After Joining the matches users Balance is not decreasing , after joining matches

Hey, How are you All? According to my thought Everybody is Fine . Today here , I am requesting to everyone to solve my issues that has been created in my Pubg tournament app. My issue is that if a user joins the matches then his/her Balance is not decreasing as it remains same. For ex- I have created a match with 10 RS Entry Fee and user have 20 RS in their wallet. After Joining the 10 RS match their, balance should decrease and becomes 10 RS in their wallet. But in my case , it is not happening after Joining the match , user balance is not decreasing. So, I request everyone to resolve my problems , otherwise there will be no values of Hard Word. As it have taken long time to built this Pubg tournament app.

I don’t see where you change the value of balance. As you said the value should decrease, but are you changing that value ?

Means there must be a block like this

When join click
   Set tinydb balance to balance -10