Download an intermediate CA certificate
In DigiCert ONE, in the Manager menu (top right), select CA.
In Certificate Manager, in the left main menu, go to Manage CAs > ICAs.
On the Issuing Certificate Authorities page, select the intermediate CA certificate.
On the Issuing certificate authority page, above On this page menu on the right, in the Download CA (paper with down arrow icon) dropdown, select the format you want to download the certificate in:
Download certificate .pem
Download certificate .cer
Save the intermediate CA certificate file.