To use Grok agents in SIP Caller, you need to create an API Key. Follow the steps below to obtain it.
Go to the xAI Platform and create your account.
Go to Settings > Billing and complete the billing setup.
Click API Keys in the left menu. Then click the Create API key button.

In the "Create API Key" dialog, enter a name and expand Advanced settings to keep only the Voice Endpoints enabled. You can also set a limit on Tokens per minute or Requests per minute. Leave the Expiry setting as No expiry so the API Key doesn't get automatically revoked afterwards.

Save the API key in a safe place, as it will not be shown again. You will need this value when creating the AI Provider in SIP Caller.