I've had a working Issue Security level in my service project for quite some time now.

I made a new Issue Type and Request Type. I need to be able to set a different Default for it. I'm confused on this set up and if it's a possibility even.
For example:
New Issue Type: Security
New Request Type: Report Security Incident
I only want two people to have access to this work , in this Service project. What can I do to achieve that with my already existing security level for project ?
(I've read this documentation so far , Configure issue security schemes | Atlassian Support)
Any advice is appreciated.