Nowhere enough information to help you.
You don't renew on your server. You renew at your Certificate provider. Your Certificate provider sends you a new Certificate and you install it manually on your server.
Please reply to these questions if you still need help:
what do you mean by 'does not renew itself'? Since it's not supposed to install itself (you're supposed to reinstall it) this isn't a helpful symptom. Do you mean that you installed it but it still shows up in your browser as with the old expiration date? If so you may want to give us your domain name so we can check it? Or use a Certificate Checking website, to check it from another source besides your system.
Are you a user of webhosting installing at the user level of DirectAdmin? Or is this Certificate used as a Server Certificate to Secure DirectAdmin Logins? Or a Shared Server Certificate?
Did you order a renewal from your Vendor?
Did the Vendor send you a new Certificate?
Did you install the new Certificate?
Did you install any new CA Intermediate Certificates sent you by your vendor?
If this is a Shared Server Certificate or a Certificate to protect DirectAdmin's login on port 2222, then please link us to the instructions you followed for the installation.
Otherwise if this is a user-level Certificate then please read and reply further:
After you created the new CSR did you do anything else in the DirectAdmin interface which would
Did the vendor send you new Certificate? Any CA Intermediate Certificate(s) (sometimes called root certificates)?
Did you install both the new Certificate (under the Private key, but leaving the Private Key in place) and any CA Intermediate Certificate(s) from the DirectAdmin control panel?
If yes to all of the above, you should also try restarting Apache manually (if it's your server) to see if that resolves the problem before replying, to see if that resolves the problem.
We look forward to seeing more information from you so we can help you further.
Jeff