If you have no current-year earnings and no future earnings, you can enter your Social Security Retirement benefit that you would receive at age 70. You would need to get this amount by signing in to your SSA.gov, your My Social Security Account.
But if you are still working, Social Security (SSA) recalculates your benefits which involves examining your full earnings history and determining if these current/future earnings will displace any of the highest 35 years in your earnings history when those years are adjusted or indexed to inflation. In the same way that SSA recalculates the benefit, MaxiFi needs to recalculate it too and, like SSA, it needs the full earnings history to make this calculation.