How to sew a Back Vent of a Double Breasted Wool Coat - No lining, Bias binding in seam allowance

Main fabric : Wool Binding tape : Sleek Bias binding in All seam allowance. No lining. The white strip is just a “PP strap“ that is often used for packing work. This is in order not to slide while sewing (sewing gap). When the thickness of the fabric is different, the pressure of the presser foot and the feed dog are not stable. Putting this tape means adding the height, this is very useful. It is used for stitch guide in this case.(03:25) 1 needle sewing machine : DDL-5571N JUKI Bar tack stitch sewing machine : LK-1900ASS JUKI