To complete Slack integration, go to the Slack Integration admin page in Jira:
Two aspects need to be configured:
In order for the integration to work correctly with Slack, you must set it up with the Bot User OAuth Access Token value, taken from location described in Configuring Chat for Slack Integration. Without it, our app will not be able to communicate with Slack.
Additionally, you should set up Signing Secret and Verification Token values, also taken from the same place. Without these values, incoming communication from Slack will not be verified for authenticity, exposing you to security risks.
In principle, you can have totally separate user identities in Jira and in Slack, which means that to send messages from Slack to JIra, you must be able to map Slack user identities to Jira user identities. The simplest way to do it is to match users automatically. This can happen if all your users have the same email addresses configured in Slack and in Jira. If this is the case, tick the Map Slack users to Jira users by their email checkbox, and thje mapping will happen automatically. If email addresses are not the same in Slack and in Jira, the mapping must be done manually, using slash commands