Delete an SSL/TLS certificate for distribution

Hi, I used some test certificates for a distribution. Now these certificates are no longer in use and distribution is disabled. I've also removed all DNS referrals although in theory this shouldn't affect it.

As indicated in the guides I should be able to delete the certificates if they are no longer in use, but no menu appears to be able to do so.

Guide references: https://lightsail.aws.amazon.com/ls/docs/en_us/articles/amazon-lightsail-deleting-distribution-certificates

Thanks