Fetch Data From Local Machine DB and Insert To Other Machine DB

Question

I need to fetch data from my laptop (Postgresql) and insert that to the main server (in a different machine) using also a PostgreSQL. In MSSQL I normally do this:

 

BEGIN TRY
    BEGIN TRANSACTION
        INSERT Main_Server.databasename.tbltransactions
                SELECT * FROM Local_Server.databasename.tbltransactions
            WHERE synchronized IS NULL

        UPDATE Local_Server.databasename.tbltransactions SET synchronized = GETDATE() WHERE synchronized IS NULL
    COMMIT TRANSACTION
END TRY

BEGIN CATCH
    ROLLBACK TRANSACTION
    RAISERROR('There was a problem connecting to the server database. The connection was lost.',16,1)
END CATCH

I need to do it using a SQL Transaction. Thank you in advance if you can show or point me to the right direction. I am very newbie in PostgreSql.