Pull the thread around the circle and pull the needle, which is equivalent to hitting a slip knot.
The second needle should pass through the middle of the knot and tie it to the other side of the fabric and wear it again.
Continue to pull the thread around the circle and pull the needle so that the two circles are connected together.
After continuing the seaming in the same way and sewing it to the appropriate length, the most critical step is taken, and the needle is passed through the last coil like this.
So as long as the line is pulled, the front knot is opened, leaving only a few small points, the traces of the line are on the back of the cloth.
Knot on the back, cut off the excess thread, and the invisible stitch is complete.