add mutations to exchange painel

app/graphql/mutations/create_buy_crypto_order.rb

@@ -9,7 +9,9 @@ module Mutations
       currency_id = decode_id(order[:currency_id])
 
       ActiveRecord::Base.transaction do
-        current_user.fiat_balance.withdrawal!(order[:amount_cents])
+        current_user
+          .fiat_balance
+          .withdrawal!(order[:amount_cents])
 
         record = BuyCryptoOrder.create!(
           paid_amount_cents: order[:amount_cents],

app/graphql/mutations/create_sell_crypto_order.rb

@@ -10,10 +10,12 @@ module Mutations
       amount = BigDecimal(order[:amount])
 
       ActiveRecord::Base.transaction do
-        current_user.balances.find_by!(currency_id: currency_id)
+        current_user
+          .balances
+          .find_by!(currency_id: currency_id)
           .withdrawal!(amount)
 
-        record = SellCryptoOrder.create(
+        record = SellCryptoOrder.create!(
           paid_amount: amount,
           currency_id: currency_id,
           user_id: current_user.id,