REST adapter OAuth JWT Signing Algorithm

Hello Experts,

I have a requirement where a call is to made to REST service and authentication is JWT where the algorithm used will be HS512 - HMAC + SHA512. I'm trying to set it up as per 2892050 - New Feature: Add Support for OAuth 2.0 JSON Web Token profile in REST Adapter .

So I selected

But dont see an option for SHA512 , the only available options are

Can you please share your thoughts on this.. is there a limitation or am I not understanding it right?

is there an alternate workaround?

Regards,

Ravi