Rename computer fixlet for windows 10 machine already on the domain

those are called secret parameters in BigFix.

They’re basically coded in the description to hide them in the console. Here’s a link that discusses it.

The basic steps would be to export the fixlet you’ve created, and then edit it in VS Code or Notepad++ or whatever you use.

In the Description field you’d add the username and password:
<Description><![CDATA[Rename Server joined to Active Directory (Secure) <script> document.body.ontakeaction = function() { TakeSecureFixletAction( Relevance('id of current fixlet'), Relevance('id of current bes site'), "Action1", {}, {secret: 'domainaccount' , secret2: 'domainpassword' } ); return false; } </script> ]]></Description>