I have generated msi installer for spark successfully , but workgroup join button will showing disable state ,how should i enable join button in workgroup

i have generated msi installer for spark successfully ,i am logon into workgroup demo successfully, but In workgroup join button will showing disable state ,how should i enable join button in workgroup.

i a m attaching my output how to enable join button
how to enable join button .docx (28684 Bytes)