Is possible to configure the max. session length in user role for never expire?
And Is not possible which is the max session length what I can configure ?
You can't set it to unlimited but you can it very, very high -
Go to user roles / role name / general / session options
Set your Max Session Length to 9999999
Set your idle timeout to 9999998 (must be at least one minute less than the max session length
Set your reminder to whatever (less than Max obviously)
This will give you about 7,000 days which is about 20 years
Or make it a little bit smaller if desired.....