How to enable API access on a Salesforce account (in Salesforce Lightning)
This tutorial is for Salesforce Lightning. If you are using Salesforce Classic, read this article.
After installing the Record Validation for Salesforce package, you need to enable API access to your Salesforce environment.
As part of configuring Record Validation for Salesforce, you need to enable API access to your Salesforce environment; either by profile or by permission sets. You will need it when working with Record Validation!
Enable API access in Salesforce by profile
Navigate to (Salesforce's) Setup > Users > Profiles
Click the profile you want to update and click Edit
Navigate to System Permissions
Tick the API Enabled box
Click Save
Enable API access in Salesforce by permission sets
Navigate to (Salesforce's) Setup > Users > Permission Sets
Select the permission set you want to update and click Edit
Navigate to System > System Permissions
Tick the API Enabled box
Click Save