What is the most logical next event?

How to teach your horse to side pass
Test your horse's ability to move away from pressure.
The natural instinct of your horse should be to move away from where pressure is applied-the same instinct humans have. Test this reaction in your horse by bumping them with an open palm near the girth where you would bump them with your calf.
They should move away from your hand, possibly already in a side pass. Continue bumping your horse near the girth with added pressure if they do not respond to you.