Switch to powder in a cardboard box, a refill station, or laundry sheets in paper. Dose by the instructions rather than the cap.
A laundry liquid bottle weighs around 100 g of HDPE; four to five a year is about 400 g avoided. Refill and reuse systems cut packaging waste to almost nothing when the container is kept in use, and the Ellen MacArthur Foundation finds returnable and refillable systems cut greenhouse gas (GHG) and water 35 to 70 percent at scale.
The catch: some laundry sheets and pods are PVA polymer; powder in cardboard is the simplest plastic-free option.