Slack Connector configuration can be managed from three different places:

• Global Setup page, which can be accessed either from Add-ons or System section in JIRA Administration. This is where you can manage global Slack Connector settings for entire JIRA instance
• Project Setup page, available in Project administration panel, allow you to configure Slack Connector for particular JIRA project
• At every issue page, by using Issue Tools, an authenticated JIRA user can control add-on settings related to given JIRA issue