How to pass API key in a secured native rest API in Outbound authentication page

How to invoke a native API and pass the API key credentials. Is it in Policy–>Outbound Authentication–>
Which option I need to select.

Hi @Giji_Alexander, can you please elaborate better your question? The IS version? What you mean by ‘native REST API’?

Hello @Giji_Alexander - Why not try out [ Custom HTTP Header]

Its not the best option, but it should work.

Best Regards,

@Franklin, Thank you. Yes, Its working.