TT is requiring me to enter RMD amount for a pension amount paid via an annuity. How to bypass the box for RMD since there is no RMD for an annuity.

If you receive your pension in monthly payments then all payments are considered RMDs.

In TurboTax, you can answer that the whole sum received is RMD and that your RMD is equal to the total received. 

This way, TurboTax will know that you have satisfied all RMD requirements.