Double stich/Mock stitch

Please help me. I´m doing a contrast color lines on baby uggs… How do i do those fake stitches on it? I once saw a video of that in youtube, but i can´t find it anymoore.
It was done just by weaving mock stitches over the main color.:??

the pattern says: “With CC, make a fake stitch line down the ‘side seams’ and across the instep, to imitate Ugg boots”

But i don´t know how to.

It’s called ‘duplicate stitch’, try searching that way.

Oh thank you so much!!! :muah: