Good afternoon good people

I have a retirement question that was asked of me but I don’t have the knowledge. The person is eligible to retire from their government job with 30 years of service and their age doesn’t factor into the equation. However they are only 54 years old. They will receive a life long pension from their employer when they retire. The question is do they then HAVE to start their social security benefits? Can they if they would want to?(That is my question…and I say they have to wait at least until 62). Their question is really can they stave off Social Security until they reach the maximum retirement age of 70 AND will they still earn Social Security credits based on their retirement pension?

I called myself looking up this information on the social security website, but… lets just say…I couldn’t find a clear response.