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
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