Neck shaping

I have run into a snag, I am working on a cardigan and go to where you start the neck shaping butttttttt, it doesn’t tell you how to do it. I have looked thru the entrie book and doesnt tell ya anything . All the pattern says( cont in color chart, noting neck shapping and raglan decs until there are 2 sts left)
Now how do I do the neck shaping when it doesn’t tell you.

It really should say in the pattern, but it may not say specifically “how to do neck shaping”.

There should be a part that says something like ‘continue with raglan shaping and at the same time decrease at neck edge X number of stitches X number of times’

Where is the pattern from?

Sometimes the neck shaping is on the chart. The chart itself will show the line of decreases row by row for several sizes. See if that’s what is happening here. Is there a link to the pattern?