2.9.6. SSL certificate format

The hosting uses SSL certificates of the standard X.509 in the format pem... It is a simple text file with between the lines ----- BEGIN CERTIFICATE ----- and ----- END CERTIFICATE ----- is placed encoded in the format Base64 certificate. The file can contain either a single certificate or a chain of certificates. The file usually has the extension crt, pem, cer or cert.

You can check or decode the certificate, for example, using the online service SSL Shopper | Certificate Decoder.

You can try to convert certificates in other formats to pem using some online converter like SSL Shopper | SSL Converter (supports conversion from DER/Binary, P7B/PKCS#7 and PFX/PKCS#12).