You're question leaves me with a few questions for you...
First, are you referring to a 'request' as something that has been submitted via the Requests tab on the Issue object or are you referring to the Request status associated with a project?
If you're referring to the request intake, you can associate an Issue level approval workflow to the Queue Topic.
If you're referring to the Request status, then you'd associate a project level approval workflow on the project that is triggered when the status = Requested and initiate this by either clicking the Submit button on the Business Case tab or manually changing the project status to Requested.
Hope this helps,
Thanks a lot ‚ for the correct response, in this scenario. We have situation number 2.
Got it now, have a nice day!