The most effective way to teach a dog to walk side by side
Use social mechanisms, something that makes her stick to the other members of the pack, not to lose sight of them. In other words, convince her that the dog can get "lost" if he falls behind or lags.
It would seem to be easy: all you have to do is walk, dragging your wingman along with you. But most owners, having barely explained to the dog what the corresponding word and gesture mean, spoil the whole event. They begin to stop, to wait, to engage in a dialogue with a donkey that is caught in a dog tag. Why? Go ahead!
Pick a bigger area, a quieter place, and walk. The "Nearby" command is very energetic, no need to sneak around or slow down. Walk! Give your dog a chance to make a mistake and see the consequences of the mistake. When he gets it right, praise sincerely and reward generously.
The person in the "Nearby" command is always the leader. Don't let the dog question that! No one wants a side-by-side command that will cause the dog to get distracted a hundred times and the human to wait for him to satisfy his desires. He Fell asleep-eaten, stopped-means he was alone. Here you have to forget everything I said about cooperation and turn into a despot. For a while, of course.
And then the praise turns on the dog's pride, followed by the desire to earn even more points by doing the command better and better. If, of course, the person behaves correctly.