Export a certificate
Go to Settings > Certificates.
For the relevant certificate, click Details.
In the Download As dropdown, select the filetype to export the certificate to.
Options include:
DER encoded binary X.509 (.CER): An X.509 certificate that contains only the public key.
Base64 encoded X.509 (.CER):
Personal Information Exchange (.PFX): PKCS#12 archive containing the X.509 certificate and private key with optional password protection.
Click Download.
The certificate is downloaded to your local storage as the specified filetype.