As a general matter, a secondary contract of employment must be supported by consideration. If an employer and employee enter into an employment agreement and then some time afterwards the employer has the employee enter into a confidentiality agreement, a court might hold that the confidentiality agreement is invalid if it isn’t supported by separate consideration. See Consideration for Change of Terms of Employment, 158 A.L.R. 231 (1945 & Supp. 2011).
If you answer “Yes,” the contract will provide for a one-time payment on entry into the contract. If you wish to structure payment differently, revise the output document accordingly.