This is a very important exercise with your dog. It gets your dog used to understanding the leash and how to move towards the pressure.
First practice this in your home for a few days. Use family members, the other dog, activities etc. Anything that can draw your dogs attention. This translates to other more difficult areas because if your dog can’t follow the leash around normal everyday distractions they well struggle around more novel distractions.
Once you feel good and understand the mechanism of pressure on and pressure off you can go outside and start introducing there. Again, start slow. Allow your dog to turn to the pressure on. You are simply getting your dog to turn it off.
Repeat this exercise in many different areas. When the context changes your dog will struggle. The more you practice the better they will generalize this leash work.