How long does it take for certificate to be generated at step 3?
Once you have modified the A and CNAME records in your DNS at step 2 and the validation is done, it can take anywhere from 5-10 mins for the certificate to be issued.
You can check if your DNS changes have fully propagated to global DNS servers: https://whatsmydns.net
If it is taking longer for the certificate to be generated, kindly contact our support mail: support@sslzen.com or contact us via beacon on our website sslzen.com.