The form is tablet based auth that doesn't have a pop up.
You need to type in domain\userid and then the password and windows authentication will occur. On the PC browser, it is assuming the current domain for the user logging in and that is why the domain is not required in the userid field.
To my knowledge, there is no configuration for the form. It will only perform windows authentication.
Please keep in mind, Qlik Sense does not perform identity verification. Out of the box, windows auth is used for identity verification on the default virtual proxy. If you want to use an alternative identity verification system you will need to roll your own login page and use the ticketing or session APIs, or header injection or SAML to perform auth into Qlik Sense.
For more information, please review this webinar on Qlik Sense security integration:QlikSenseSecurityIntegration.mp4 - Google Drive
Hope this post find you in best health.
I am facing same issue. Can you tell me how you resolved this issue.
For me on local system login form open and i can log in. But when i try to access through other system using public IP (Assigned to server) Form doesn't open and it just give error.
Note: I can open app using Anonymous access.