Issue is the owner of the dashboard is no more available and I am not the owner of the Dashboard
Could you please first tell me you are jira end user or jira administrator?
if you are jira user, then Contact with your JIRA Administrator. JIRA administrator has permission to change the owner of dashboard.
I am a JIRA administrator.. But unable to see those options available in there
I am a JIRA administrator.. But unable to see those options available in there