How to grant execute permisson on sproc to access users.

Users are getting the triggering an ODBC error that says Execute Permission Denied when a pass thru query is run that calls a sproc in SQL Server.

How do I grant them permission to run the sproc.

//* ms access code ////////////////////

Private Sub cmdQueryConnect_Click()

Dim myDB As Database
Dim qdfPassThrough As QueryDef
Dim vUSA, vCAN, vMEX, vCountry, vPartNum, vPartDesc, vStockClass As String
Dim vCustName, vSupName, vBeginDate, vEndDate, vUserName, vSQL As String

Set myDB = DBEngine.Workspaces(0).Databases(0)


/* code for populating  variables from form goes here */
       
 vSQL = "EXEC dbo.pc_QueryConnectData " & vCountry & ", " & vPartNum & ", " & vPartDesc & ", " & vCustName & ", " & vSupName & ", " & vStockClass & ", " & vBegDate & ", " & vEndDate

             
 
DoCmd.Close acQuery, "queryConnect"
DoCmd.DeleteObject acQuery, "queryConnect"

Set qdfPassThrough = myDB.CreateQueryDef("queryConnect")
qdfPassThrough.CONNECT = "ODBC; Driver={SQL Server};Server=DDDRENM112;Database=ConnectTest;Trusted_Connection=yes;"
qdfPassThrough.SQL = vSQL
qdfPassThrough.ReturnsRecords = True

DoCmd.OpenQuery "queryConnect"   <---- ERROR occurs here
DoCmd.SetWarnings False

End Sub

/* SPROC CODE */

SET QUOTED_IDENTIFIER ON
GO
SET ANSI_NULLS ON
GO

/* DROP PROCEDURE [dbo].[PC_QueryConnectData]  */


CREATE PROCEDURE [dbo].[PC_QueryConnectData]

(@CustCountry varchar(20),
 @ItemCode varchar(20),
 @ItemDesc varchar(30),
 @CustName varchar(80),
 @POSupName varchar(80),
 @COPCLSCD varchar(4),
 @BegDate datetime,
 @EndDate datetime
 )

AS

SET NOCOUNT ON
( NOTE : the select statement below runs fine on its own )
SELECT T_ConnectFlatFile.CUS_COUNTRY, T_ConnectFlatFile.CUS_CURRENCY,
 T_ConnectFlatFile.COPCLSCD, T_ConnectFlatFile.ITMID,
T_ConnectFlatFile.ITMDESC, T_ConnectFlatFile.ITEM_CODE,
T_ConnectFlatFile.ITEM_DESC, T_ConnectFlatFile.REC_DATE_TIME_PST,
T_ConnectFlatFile.REC_QUANTITY, T_ConnectFlatFile.UNIT_COST,
T_ConnectFlatFile.TOTAL_COST, T_ConnectFlatFile.CUS_NAME, T_ConnectFlatFile.CUS_CITY,
 T_ConnectFlatFile.DEALER_LOC, T_ConnectFlatFile.REC_SUP_NAME
FROM dbo.T_ConnectFlatFile
WHERE (@CustCountry is Null or CUS_COUNTRY = @CustCountry)
AND (@ItemCode is Null or ITEM_CODE LIKE @ItemCode)
AND (@ItemDesc is Null or ITEM_DESC LIKE @ItemDesc)
AND (@CustName is Null or CUS_NAME LIKE @CustName)
AND (@POSupName is Null or REC_SUP_NAME LIKE @POSupName)
AND (@COPCLSCD is Null or COPCLSCD LIKE @COPCLSCD)
AND REC_DATE_TIME_PST BETWEEN IsNull(@BegDate, REC_DATE_TIME_PST) AND IsNull(@EndDate,REC_DATE_TIME_PST)





GO
SET QUOTED_IDENTIFIER OFF
GO
SET ANSI_NULLS ON
GO