Go to your user task node and add a new input via Node UI designer.
2
Now go back to the process and add a new action rule:
first we need to configure the action - the action is called when the button is pressed - the action should be Manual (not automatic because it is triggered by a user)
we need to keep in mind the name of the action - saveDataFirstStep
3
Go back to the Node UI designer and add a button (we need to link the button to the action based on the name).