If you recall, in Chapter 5, Salesforce Einstein Vision, we covered the authentication mechanism for accessing the Einstein Vision API. We used Private Key (this was downloaded from https://metamind.io/), and then signed the payload comprising of accountId and requestUrl using JWT (RSA 256) to obtain an access token in return. This section will cover the code and configuration needed in Salesforce to obtain the access token. We will assume that we will store the Private Key securely in the Salesforce files.
Salesforce Files are replacing the Salesforce attachments. You can read more about the Salesforce Files and attachments at https://help.salesforce.com/articleView?id=collab_files_overview.htm&type=0.