Fetch merchant wallet balance

this api fetch merchant wallet balance

GRAPHQL

Fields	Type	Description	Example	O/M	Data Management
URL	string		`{base_url}/graphql/loop-merchant-payments-service`	M
GRAPHQL	string		QUERY	M
content-type	string	JSON	application/json	M
x-access-token	string	Session token with validity	token	M	Merchant's token

{
  query: {
    merchant_wallet(){
      expense
    }
  }
}

{
"expense": 400
}