If the inmate and the visitor are eligible for a contact visit, then you do not normally have to request one. Inmates who are subject to disciplinary procedures may be denied a contact visit even if the visitor is eligible for one.
Only close family members are normally granted contact visits unless the inmate is in a Trusty camp, or unless the non-family member requests it in advance.
Only in some circumstances will the Warden or duty warden grant a contact visit for a non-family member and this will depend very much on the individual circumstances of the inmate and the visitor at the time.