Step 1- Create your stored procedure in the B1 Database using a SQL script.

Step 2- Create a new query in the B1WebAPI category inside the B1 client with syntax like this:

DECLARE @MinDays INT
DECLARE @DocDateType VARCHAR(3)
DECLARE @Reconsiled VARCHAR(3)
DECLARE @AgeDate DATETIME
SET @MinDays = 0
SET @DocDateType = 'POS'
SET @Reconsiled = 'NO'
SET @AgeDate = GETDATE()

EXEC dbo.V33_QueryAgeReport [%CustCardCodeFrom] , [%CustCardCodeTo] , @AgeDate,@MinDays,@DocDateType,@Reconsiled

Step 3- Call that query via the B1WebAPI and pass it the required parameters.

The B1WebAPI will pass that information to the query you saved in B1, execute the stored procedure with those params and then return the results.