Let's see how you can get an access token from Salesforce to access the Salesforce API's.
- Create a developer account for Salesforce in https://developer.salesforce.com/signup
- Navigate to Setup ➤ Create ➤ Apps, and in the Connected Apps section, click New to create a new connected app.
- To create a new app, you have fill the basic information as follow and then click Enable OAuth Settings to open the API section. In Enable OAuth Settings, you have to add the scope and need to put the callback as follow and save the configurations.
- Once you save the configurations, you can see your Consumer Key and under API (Enable OAuth Settings).