Update Message Format

Step 1: Log in to JIRA Server as an administrator

Step 2: Select your Current Project from "Projects" dropdown on the top menu

Step 3: Expand the left menu, click on 

Step 4: At the left hand side, scroll down until "Slack Integration" option 

Step 5: Click on Configure

Step 6: Choose Message format tab

Step 7: Modify message then click on Send Test to view the result which is already sent to configured channel

Create a JIRA ticket:

Step 1: Log in to JIRA Server

Step 2: Click on  on the top menu 

Step 3: Create a JIRA ticket

Step 4: Open Slack channel