You are attempting to define a password in its encrypted format (the "7" means use the highest encryption level when running config is displayes).
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I think that you need to leave out the "7" from the command. This is because the "kkk123" value is not a supported encryption string, therefore the Cisco will give an error. instead, if you want the password as "kkk123" and the user as "test123" then type this.
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Router(config)#user test123 password kkk123
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This should do it.