How to use predictnl in stata

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How to use predictnl in stata

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I have an issue with the command predictnl.

I want to predict the risk of developping breast cancer according to age at the first pregnancy and age at diagnosis. I have tried this:

predictnl or = exp(_b[Age1FT] + _b[FT] + _b[AgeDiag#c.FT]), ci(lb ub) p(pval)

but it gives me the same value at every points. If I try to predict to risk for a women who has given birth at 20 and was diagnosed at 25 years
predictnl or = exp(_b[Age1FT]*20 + _b[FT] + _b[AgeDiag#c.FT]*500), ci(lb ub) p(pval),

I still have the same value for all the other ages at first pregnancy.

Please can somebody help me on how to write the correct synthax in order to obtain an unique value for each point?

Thank you in advance.