1. Login to cPanel (https://domainname.com:2083 OR https://IPAddress:2083)
2. Go to Email Deliverability.
3. Select your domain name and click on Manage.
4. This section will show the DKIM record for your domain. From here can copy the DKIM record and then paste to the DNS Zone to update the DKIM or you can set in the same page.
5. Lastly, once the DNS propagation done, the DKIM record will show VALID.