The info about the indexes says......(see below where it tells you that "The details found in the GRO indexes will allow you to purchase the original certificate from the General Register Office." ) So why can't they provide the cert,with all the correct details from the index?
The British armed forces and overseas births and baptisms pulls together records from the General Register Office (GRO) and The National Archive (TNA) to create one expansive collection. Below we have provided a full list of sources including the archive and series information. Within the collection, you will find birth records from families of military personnel, British Consul staff, and British nationals working overseas, as well as, individuals born at sea. The details found in the GRO indexes will allow you to purchase the original certificate from the General Register Office.
If you have a relative or ancestor who was born overseas but was still classed as a British citizen at the time of the birth, then it is quite possible that the British Consul or the UK High Commission in the relevant jurisdiction would have been notified of the birth, allowing you to find the record within the General Register Office Consular indices.
The armed forces records include the registrations of British armed forces (including serving members who were not British nationals) posted overseas. This index also includes some regimental registers and chaplains' returns for army births which took place in the British Isles, for example, at barracks and garrisons.
The records include births of the children of passengers, seamen, and Royal Marines, of both British and other nationalities. Some of the records contain notes about conditions surrounding the birth, such as premature confinement, if the child was stillborn, or if the mother was unmarried.
Most of the records found in this collection were previously available as separate record sets on Findmypast as British nationals born overseas 1818-2005, British nationals armed forces births 1761-2005, and Births at sea, 1854-1960. We have combined the various record sets and added additional records from The National Archives to create this extensive collection.