Shape raglan

hi everyone … i make a sweater for my son on the round without pattern so i want to shape raglan like the PC and i do not know how i dec to shape raglan that way for the body and sleeve… could you help please… thank you

You’re working bottom up? You can decrease on each side of a marker which is similar to the raglan in the photo. You can also mark a stitch or two as center stitches and decrease either side of those stitches.
This video shows the decreases with 4sts between and also shows how to dec on every row. Usually you would dec every other row but you could change that if you wish.