SQL Server Error: The EXECUTE permission was denied on the object

i use this code.

but i still get thi error like :

The EXECUTE permission was denied on the object 'sp_OAMethod', database 'mssqlsystemresource', schema 'sys'.

Declare @Object as Int;
DECLARE @hr  int
Declare @json as table(Json_Table nvarchar(max))

Exec @hr=sp_OACreate 'MSXML2.ServerXMLHTTP.6.0', @Object OUT;
IF @hr <> 0 EXEC sp_OAGetErrorInfo @Object
Exec @hr=sp_OAMethod @Object, 'open', NULL, 'get',
       'http://;', --Your Web Service Url (invoked)
       'false'
IF @hr <> 0 EXEC sp_OAGetErrorInfo @Object
Exec @hr=sp_OAMethod @Object, 'send'
IF @hr <> 0 EXEC sp_OAGetErrorInfo @Object
Exec @hr=sp_OAMethod @Object, 'responseText', @json OUTPUT
IF @hr <> 0 EXEC sp_OAGetErrorInfo @Object
INSERT into @json (Json_Table) exec sp_OAGetProperty @Object, 'responseText'
-- select the JSON string
select * from @json
-- Parse the JSON string
--SELECT  FROM OPENJSON((select  from @json), N'$.elements')
--WITH ( 
--  [type] nvarchar(max) N'$.type' ,
--  [id] nvarchar(max) N'$.id',
--  [lat] nvarchar(max) N'$.lat',
--  [lon] nvarchar(max) N'$.lon',
--  [amenity] nvarchar(max) N'$.tags.amenity',
--  [name] nvarchar(max) N'$.tags.name'   
--)
EXEC sp_OADestroy @Object

how to solve this error.