Go to Creation > Certificates.
​​Result: The list of certificates is displayed.

Search for your certificate. More info.

Click the three dots next to the certificate you want to edit.

Choose Edit.

Make the necessary changes in the Edit certificate form.
You can, for example, change the name, add an extra assignment or choose another template for the certificate.

Click Save.
​Result: The changes will apply to future certificates. Existing certificates will not be changed.