You make this yourself. We do not sell these. Just take a flat board and lay 230 grit sandpaper, rough side facing up, on the board. Stand a squeegee straight up on the sandpaper, and support the squeegee in the vertical position with bars on either side of the blade. The bars can be made from metal, Delrin as shown, or other material. Screw the bars down in position.
To use, simply slide the squeegee down the track before printing each job. That keeps a sharp edge on the blade. If blade edges have already been rounded from repeated printing, then the Squeegee Sharpener will not help. A carpenter with a bench sander can square the edge to give you a new starting position.