'DKIM cannot be enabled for the domain as no verified default selector present'

'DKIM cannot be enabled for the domain as no verified default selector present'

I'm trying to sort an error I have regarding DKIM. I have a notification in my mailbox which says 'DKIM entries in your domains DNS are not configured to match with Zoho. Configure DKIM for better email deliverability.'

When I click to see what the error is, this comes up

'DKIM cannot be enabled for the domain as no verified default selector present'

Any help?