1. On n8n's main dashboard, go to the 'Credentials' tab.
2. After that, click 'Create Credential' in the top-right corner.
3. Browse the list of apps, then select 'Perplexity AI'.
4. Tap 'Continue' afterwards.
5. Following that, prepare your Perplexity API key and then enter it into the provided input field.
6. Subsequently, click the 'Allowed HTTP Request Domains' if you wish to adjust its default configuration.
7. Once done, click 'Save' to apply the changes.
8. Finally, your Perplexity API key will be added as a credential in your n8n workspace.