What is a necessary step when using external callouts with Local Actions?

When using external callouts with Local Actions in Salesforce, one necessary step is to whitelist the domains. This process involves specifying which external domains are allowed to be accessed by your Salesforce environment. Whitelisting domains is crucial because it ensures that your application can securely communicate with trusted external resources while blocking potentially harmful requests from untrusted sources. This step is vital for maintaining the security of your data and applications, as it helps prevent unauthorized access and data breaches.

While configuring a proxy server, enabling browser notifications, and integrating with APIs may be components of working with external systems, they are not specifically required for allowing Local Actions to make callouts to external domains. Whitelisting is the definitive step that directly impacts the behavior of external callouts in the context of Local Actions, making it essential for proper functionality and security.