Help with adding an elastic band

I have knitted a baby outfit and the pants call for an elastic band at the top. I’m pretty sure I can’t get the yarn through the elastic. Does anyone have any idea what I should use to sew the elastic into the waist?:??

You can make a hem for it and thread waistband elastic that’s sold in the sewing notions through it. I’m not sure it means a rubber band type elastic band, but you could put a rubber band over the piece (with WS facing) and fold over the hem and sew the hem in place, not the band.

Depends on what yarn you’re using but you should be able to knit several extra rows of stockinette, enough rows to wrap over the elastic (making a casing) and then whip the bind off edge back to the inside of the pants. Leave a space large enough to thread the elastic through and around the pants, then securely stitch the ends of the elastic together. Then finish whip stitching. Your elastic will be covered and it’ll look much neater than just stitching the elastic to the pants top/waist.