Create an intermediate CA
In DigiCert ONE, in the Manager menu (top right), select CA Manager.
In the account menu (top right), select the account you want to add the intermediate CA to.
In the CA Manager menu, select Manage CAs > Intermediates.
Select Create intermediate CA.
Select how you want to issue this intermediate CA.
Select the HSM provider and partition to save the keys to (optional).
Select the DigiCert CA you want to sign and issue from.
Change pathlen and issuance settings or accept the defaults.
Select a template and settings.
Enter a common name.
Enter a validity period.
Select an organization.
Add organizational units and certificate policies. (optional)
Select Next.
Change root CA configuration or accept the defaults.
Select Create.