Locations: choose Chatter Tab and publisher as of now. but you can select one or more based on the where you want to show this the canvas on salesforce. Now final connected App is looking as shown below.
Now you need to enable the app for the profiles or users. To do this,
Click on the Manage on the connected App which you created in above .click edit policies
In the OAuth policies select Admin approved users are pre-authorized for the Permitted Users field and save it
In the Profiles related list add the profiles which you wanted to grant access.
Building Your App on Node Js
Let’s set up the basic app structure. We will use Express to set up a basic Node application. Here is the below package.json file which we will use to build the node js application. Application folder structure is shown below.
Now go to the Connected app which you created in earlier, update the callback URL and Canvas App URL with the Heroku app URL example https://shrouded-dawn-91712.herokuapp.com. We have to add the environmental variable to the Heroku app with the Consumer secret from the connected app. Run the below command to set the environmental variable
heroku config:set CONSUMER_SECRET=xxxx
Here is the lightning component that will invoke the canvas app