I'm using a custom picklist LWC Component and whenever I click on the next without selecting any picklist value, it allows me to go to the next component. Is there any way to validate this?
Eric Praud (Activ8 Solar Energies) 
Forum Ambassador
Sorry, when I answered, the screenshot in your question wasn't showing (issue on my side).
This is a custom component, hence why you don't have the Require checkbox.
Is there a way you could use the standard Picklist component?
Otherwsie, you would need:
A display text for your error mesaage, where you would set the visibility to some checkbox variable equals true
Straight after your screen, add a decision to see if your picklisyt is null. If it is null, go to an assignemnt where you set the checkbox var to true and go back to the screen
If it is not null, carry on with your flow
