Making baby booties

I am making baby booties and in the instructions row 3 says k 2 *YO,P1,P3tog,P1,YO,K1; rep from * across ending last rep with K2 so my question is when I am done with that the next row, Row 4 it say purl how do I purl the yarn overs when I come to them in row 4

Just purl them as if they were regular stitches. They will create an eyelet.

Thank u

If you want to see it done: https://www.youtube.com/watch?v=Iao3TNNKW9c