Help with OIDC F5 Setup

Experts,
Need help with OIDC F5 setup 
apm inactivity timeout = 15min. Once inactivity is reached redirecting to F5 'vdesk/hangup' page.
Expectation - Once inactivity is reached must redirect to idp login page.
Any iRule snippet you can include, would be great to achieve above expectation.
Any inputs, appreciated.