The Jira Administrator permission is key to being able to grant many other permissions in Tempo, such as any Jira Global permissions or Project Permissions.
To get the Jira Administrator permission, you must be added to a Jira group which has these permissions, such as the jira-administrator group. Another Jira Administrator or Jira Site Administrator can do this for you.
Once you have Jira Administrator permissions, you can add others to groups which have this permission. Of course, this permission should only be granted to those who need high-level access to your Jira and Tempo site.
To grant Jira Administrator permissions:
Go to Jira settings > System > Global Permissions.
At the top of the page, under Administer Jira, add a user to a group which has this permission.