One way to create a Jira Service Account (to use with Jira Align) with the correct permissions is to first create a group and assign it the correct permission scheme.
1. Navigate to Administration > User management > Groups.
2. Add group. In the example, I used "jira-service-acct" as the Group Name.
3. Navigate to Administration > Issues > Permission Schemes.
4. Click Add permission scheme.
5. Grant the permissions according to this chart.
6. Navigate to Administration > User management > Users. Click Create user.
Note: For Jira Cloud, this window will ask you to Invite Users as opposed to creating them.
7. Navigate to Administration > User management > Groups. Click Edit members next to your Jira Service Account Group name.
8. Type in the Service Account username in the Add members to selected group(s) field and click Add selected users.