Resolve this error I am getting in this SSIS Package?

So I created an SSIS package that retrieves a dataset through a SQL query, then converts the data type, puts the data through a lookup so that only new records are inserted, and finally the lookup inserts the data into the destination database. However I am getting this error that I'm not understanding, where am I going wrong with this?

The error code attached below.

[OLE DB Destination [42]] Error: SSIS Error Code DTS_E_OLEDBERROR. An OLE DB error has occurred. Error code: 0x80004005. An OLE DB record is available. Source: "Microsoft SQL Server Native Client 11.0" Hresult: 0x80004005 Description: "The statement has been terminated.". An OLE DB record is available. Source: "Microsoft SQL Server Native Client 11.0" Hresult: 0x80004005 Description: "Violation of PRIMARY KEY constraint 'pk_Lead_Transaction_ID'. Cannot insert duplicate key in object 'SF.Opportunity'. The duplicate key value is (211806634).".