Player Mark id=unknown in ADM files so how do I whitelist them?

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    I have a new server and I want to whitelist a player. They tried to join and when i look them up in the ADM logs it shows their name Mark (id=unknown)

    SO how am i suppose to whitelist them if I cannot get their id?

    Also what ID does Nitrado use because the GUID isnt correct and wont let them join when I get that value using a converter. Thanks for your help!