Requested update, a) is that Actions → Flow … now seems to have been replaced with Actions → Triggers and b) in the ‘Associate the Action with a Flow’ section, it’s not clear whether the plugin automatically works or you specifically need to drag the ‘Password Rotation’ widget into the flow, mid-screen, between Start and Complete icons. Also if you have pre-existing widgets in place (as I do), does that ‘Password Rotation’ widget get placed before or after that?
You are right, Actions → Flows became Actions → Triggers since the introduction of Forms for Actions. This measure was helpful because it eliminates confusion as Forms also have a component called Flows. This video explains how Forms can be used: Extend Auth0’s capabilities with Forms for Actions
In the ‘Associate the Action with a Flow’ part it is necessary to drag the action into the Flow(now called Trigger) for it to work.
If you have other Actions in the Trigger you have to decide where to place it based on your use case. Take note that each action is executed in the order in which it was placed. You can find in detail information about the way Actions work in this documentation: Understand How Auth0 Actions Work.
If you have additional questions, don’t hesitate to come back to the community.