Grafana config with CAS Auth

I installed the latest stable version from Grafana 7.2. Now, I want to add SSO CAS auth to grafana but I don’t know how to config custom.ini in grafana conf.
I already have CAS server.
My cas sso using mod_cas (via
My login url:${myServiceUrl}
After redirect and login, my url return:
A request like:${ticket}&service=${myServiceUrl}
was sent to get xml cas:user username.
How can I config my grafana to auth with cas sso?
I have read many post about this but don’t have any solution. Please help me.
Thank you.