How to knit a beak for a duck?

I’m working on a flat eyeglass holder with a duck face. Trying to find how to knit a projecting beak that opens. Thank you

I’ve not tried a duck beak but I have picked up sts for bear ears. Once the eyeglass holder is finished pick up in a slight curve whatever number of sts will give you the size beak you need. Knit and shape the beak then bind off for the upper beak. Work a similarly curved or even straight lower beak and you should have the look you want. You can always practice the pick up, curve and shaping on a swatch.
An alternative is to cast on the sts and knit the top and bottom of the beak separately then seam to the holder.