Restrict commenting on closed tickets to a project role

[Whitni Smith]

I'm looking to restricting comments on closed tickets to a specific project role. 

Based on this https://confluence.atlassian.com/adminjiraserver/workflow-properties-938847526.html it's possible by adding to the properties on the transition 

jira.permission.comment.projectrole=YourProjectRole

However, when I put that in to the properties section as such

Property Key input is "jira.permission.comment.projectrole" 
Property Value input is "Developers" 

Is restricts even viewing the tickets

I've even tried 

Property Key input is "jira.permission.comment.projectrole=Developers" 
Property Value input is "true" 

and it has the same behavior. 

and no we do not have the line that denies comments for all closed tickets to all in the properties. 

[Whitni Smith · Accepted solution]

Answer to my own question, you need to use the projectrole ID numeric value instead of the text string value which can be found 

System > Project Roles (under Security heading) 

This is solved, 

Answer: 
jira.permission.comment.projectrole = $projectroleID