Sydnod use below public keys for certificate authentication. Choose your flavor.
ssh-rsa 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
SHA256:VB9NuVB5mh/dLDv3pZBetJoyRCnTKRZace4O4t2kHR0
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
C5:AB:43:9C:B9:D8:02:C6:76:15:EB:F6:68:46:6F:D5:E2:2A:0F:E7