Steps to follow to add members to a Workflow
Go inside a workflow by clicking on Workflows option at the left, and you can see all your workflows listed there.
Select the workflow in which you want to add a member. For example - I have selected 'Leads' Workflow.
In this page, at the top right beside 'Edit Flow' button, a 'Bell' icon is there. Click on that.
A list will open with all the notifications in this workflow, with latest at the top.