Test Slack team_join event with Postman - postman

Question

I've followed this Slack tutorial to create an onboarding bot that gives people a few tips on how to interaction with other members. The tutorial recommends using Postman to test onboard experience, but it's not clear on how. I'm getting stuck on this: where do I put the a authorization token?
Prereqs:
ngrok is running on port 9292
rackup was run to start the server
I followed all steps to configure the Slack app as shown in the tutorial
I clicked the Slack button to authorize the application
What I'm doing:
Using Postman macOS client to send this default JSON event for team_join to the /events endpoint:
{
"type": "team_join",
"user": {
"id": "U023BECGF",
"name": "bobby",
"deleted": false,
"color": "9f69e7",
"profile": {
"first_name": "Bobby",
"last_name": "Tables",
"real_name": "Bobby Tables",
"email": "bobby#slack.com"
},
"is_admin": true,
"is_owner": true,
"is_primary_owner": true,
"is_restricted": false,
"is_ultra_restricted": false,
"has_2fa": false,
"two_factor_type": "sms"
}
}
I've tried including token as a parameter, header key/value and within the JSON object. None of these approaches seems to do it and it results in an authorization error. I get Invalid Slack verification token received: or a parsing issue.
How does one test something like a new user joining using this setup?

Answer 1

The token is available within the Event envelope, so you'll need to go up one level in the JSON:
{
"token": "{{verification_token}}",
"team_id": "{{team_id}}",
"api_app_id": "{{app_id}}",
"event": {
"type": "team_join",
"user": {
"id": "{{user_id}}",
"team_id": "{{team_id}}",
"name": "{{user_name}}",
"deleted": false,
"status": null,
"real_name": "{{user_real_name}}",
"profile": {
"first_name": "{{user_first_name}}",
"last_name": "{{user_last_name}}",
"real_name": "{{user_real_name}}",
"real_name_normalized": "{{user_real_name}}"
},
"is_bot": false
}
},
"type": "event_callback",
"authed_users": ["{{authed_user}}"]
}