Error while creating APNS certificate

For creating APNS certificate, we use a signed CSR from our MDM vendor which is a .plist file. We were using this for quite some years now. But currently APNS portal throws error saying invalid file type (as attached below)

Is the Portal updated to support only .csr / .txt / .rtf? Can anyone help to use the correct file format. (P.S: Works if we edit the extension & upload it)

When requesting a new MDM push certificate you upload a base64 encoded plist file. There's no standard file extension for such a file. I suggest renaming the uploaded file so it ends with .txt since base64 encoding is a text format.

Error while creating APNS certificate
 
 
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