Administrators have to specify company-wide app settings, setup default values for new charts, and configure Jira fields that are used by Gantt Suite.
App configuration is accessible from Jira settings → Apps → Gantt Suite → Configuration:
Gantt settings
These are default values only for new charts. Existing charts aren’t affected by changes.
Task start field defines a Jira field to use to store Gantt Suite custom information. Gantt Suite will try to create and pre-select a Jira custom field named Start Date [Gantt].
In order for app to work correctly, the field must be added to Jira screens on projects where app will be used. See Scope for more info how this field will be used.
Calendar
These are default values only for new charts. Existing charts aren’t affected by changes.
Basically the same configuration regular users see when creating a chart Calendar
Security
Allow impersonated view is NOT a default value. It affects all charts, existing and new. It is only visible to Jira administrators.
Normally, users without permissions to access projects or issues will not see them on a chart either. This option lets chart creators to allow users with restricted access to see tasks on a chart in view-only mode. In other words, it allows users with restricted access to see chart the way chart owner does.
When this company-wide option is turned on and chart creator also turned impersonation on, app impersonates as chart creator for Jira issues and links loading. All other operations are NOT using impersonation.
Links configuration
These are default values only for new charts. Existing charts aren’t affected by changes.
Basically, the same configuration regular users see when creating a chart Links configuration