Thanks for clarifying that you'd also like [new request].

The current agreed deliverable is [existing scope]. The additional request changes [quantity, audience, direction, integration, or format].

I can offer:
A. Add it: [extra deliverable], with [proposed fee] and [revised date].
B. Trade scope: replace [existing item] with [new item], subject to [revised terms].
C. Keep this project as agreed and scope the addition separately.

My recommendation is [option and concrete reason].
Please confirm the preferred option. I will document the revised scope and wait for agreement before starting the additional work.

Before sending: if this is a correction to your own work or an already-included revision, address it under the existing agreement instead. Do not invent fees or clauses.