Qlik Sense does not perform identity management and/or verification. As a result, no passwords are stored in the repository.
Qlik relies on external parties to perform identity management and verification. By default, Windows auth is supported out of the box and your initial user is likely a local account on the Windows server you installed Qlik Sense server on.
User directory connectors like the excel version you are creating are for importing attributes into Qlik Sense for authorization purposes. It is not a facility for identity management or verification.
Please have a watch of this video on Qlik Sense securty: https://www.youtube.com/watch?v=vkCh_t1nd40
In addition, please mark responses helpful or answered so that others with similar questions can benefit.
Does it has to be through EXCEL? you can try creating a new user in "Computer Management" and add him in to QMC. Here you can define a password. Usually if this created user is on same machine where QMC/Qlik Sense is installed then it will automatically add them, if not just sync the user directory connector..
I haven't tried uploading user attributes through excel, so not sure how to define them. I will try and let you know.