Canvas admins can enable the Slack feature option for a Canvas account. However, to enable Canvas notifications for all users within a Slack workspace, a user with Slack admin rights must create and install the Slack app to create a Bot Access Token. After the bot is created and verified, individual Canvas users can enable Slack as a Canvas contact method to receive notifications.
In Canvas, click the Settings link  in Account Navigation. Then click the Feature Options tab . Enable the Slack Notifications feature option .
To configure Slack for all users in a Slack workspace, a Slack app and API key must be created.
To create a Slack app and API key, open api.slack.com/apps in your internet browser.
If necessary, log in to your Slack account.
Click the Create New App button .
Give the app a name in the App Name field . The app name will display to users in the Slack workspace.
Select your institution's workspace or the workspace the app should belong to in the Development Slack Workspace drop-down .
To create the app, click the Create App button .
Open the OAuth & Permissions page .
In the Scopes section , click the Add an OAuth Scope button .
Click the Add permission by Scope or API method drop-down menu  and select the following OAuth scope options:
To save and install the app, click the Install App to Workspace button.
A message displays requesting permission for the app to access the Slack workspace.
Click the Allow button.
Once the app is created in Slack, click the Install App link .
Locate the Bot User OAuth Access Token and click the Copy button .
In the Account Settings page in Canvas, locate the Slack API Token section and paste the copied token in the New Slack API Key field .
To save, click the Update Settings button .
Note: If the Slack API Key heading does not display, refresh your browser window.
In your user settings page, click the Add Contact Method link .
Click the Slack Email tab , and enter the email address of your Slack account in the Slack Email field .
Then click the Register Slack Email button .
In Slack, look for a notification sent to the newly-created Slack App with a four-digit Canvas registration code .
In Canvas, enter the four-digit code in the Confirm Communication Channel field . Then click the Confirm button .
Once confirmed, all users in your Slack account can now add the Slack Email contact method and manage their Slack notification settings in the User Settings page.