Slack Spoke and collaboration is not adding users to channel


[ ] Customer is using slack spoke and Collaboration services 
[ ] Trying to add multiple users from the UI action of Incident form's  "Create Slack Channel"
[ ] But could see only one user is getting added


Make sure the slack ID and is listed under the slack cache. Once all the ID's are proper, please make sure the Signing secret record is properly configured


Follow the below documentation to configure the record under the heading - Provide Signing Key in ServiceNow instance and also make sure the interactivity URL follows the pattern documented under Configure Slack app, in step 6