How to enter fed. tax withheld from a federal annuity? Also, "additional payments" box only allows a specific date, but tax was withheld every 2 weeks. How to enter?

To clarify, do you have a 1099 for the annuity and if yes, is the tax not reported in Box 4? 

Do you get an Annuity payment every 2 weeks?  How are you withholding taxes every 2 weeks?  Did you get a 1099R for it?  What code is in box 7?  Isn’t all the withholding in box 4?  This doesn’t sound right.