You should go into the BIM Server Control Center on the computer where the BIM Server is installed, and open the Server Manager from there. In that case you will not need a password to get into BIM Server Manager and to manage it.
Here it is assumed that if you are a person with enough privileges to log into the server machine, then you probably also have enough privileges to manage the BIM Server. Hence no need for password on the BIM Server machine.
Then go to the User Dialog of the person and change its password. With that password you wil be able to manage the BIM Server from other machines.
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