Pattern help

I’m on the fourth row of border pattern I’ve got to cast of 5sts, the border pattern is k1 p3tog k1p1k1 all in the same stitch the instructions say if on row pattern 4 work p3tog in the casting off please help very confused.

What is the name of your pattern?
Can you give us the exact direction for the 4 border rows?

Hayfield Babylon 1115 18-24” DK

https://www.ebid.net/au/for-sale/1115-hayfield-knitting-pattern-baby-child-cardigans-dk-18-24-186686862.htm

If this is the pattern, the front panels look like the raspberry or blackberry stitch.

If you are up to a cast off, then p3tog at the appropriate stitch. That’ll leave one stitch on the right hand needle. Work that stitch as part of the cast off. Bring the first stitch on the right hand needle over this stitch and off the needle.