Apply F5 marketplace rule group to AWS WAF web ACL cloudformation template

I'm struggling with the same issue for the API Gateway set of rules. One of my colleagues was able to get information using the following CLI command to get the rule group id:

aws waf-regional list-subscribed-rule-groups

But, I'm still struggling with the cloud formation side to define a parameter listing the Rule Group ID and then create a WebACL for our teams to apply to their applications. I'm trying the following:

Parameters:

  RuleGroup:

   MetricName: F5APISecurityRules

   Name: F5 Rules for AWS WAF - API Security Rules

   RuleGroupId: 5a27a101-5fde-415d-9940-77f21867b80f

Reseources:

 APIWAFWebACL:        

  Type: AWS::WAFRegional::WebACL

  Properties:

   Name: "APIWAFWebACL"  

   DefaultAction: 

    Type: "ALLOW"

   MetricName: "F5APISecurityRules"

   Rules:

    - 

     Action: 

      Type: "BLOCK"

     Priority: 1

     RuleId: 

      Ref: !Ref RuleGroup 

Anyone had any success?

Thanks!