Until today, for a user to complete a flow they had to visit a step that you had explicitly marked as a completion step in the flow builder.

We realized that this is in most cases unnecessary work. We now automatically mark the last step of a flow as the completion step. It will be shown as a gray checkered flag in the builder:

It even works if you have multiple last steps, i.e. if your flow branches into 2 paths:

You can overrule the automatic completion step(s) if you want. Simply click a step's settings block and then enable Explicit completion step. Notice how Step 2 now has a green checkered flag and Step 3 is no longer a completion step: