You can renew an existing certificate by following these steps:
Click Server Certificates tab > Certificate Name > Renew button.
Provide Token Information
Enter the password for the token if required. Otherwise click Next to continue.
Update Certificate Details
Review the certificate details and provide the validity period in months.
Update Key Information
For key type, you can choose RSA or ECC. If the key type is RSA, the key size can be 1024, 2048 or 4098. If your key type is ECC you will also need to select a curve. Keep in mind that generating a new key pair takes time.
This page provides you with the summary of selected options. Click on Finish to complete the renewal process.