飛行機の予約を再確認するために必ずしも空港へ行かなくてもよい。

。

You don't necessarily have to go to the airport to reconfirm your airplane reservation.

Literal

Airplane [possessive-の] reservation [object-を] re-confirm [in order to-ために] necessarily airport [to-へ] go-not-even-if is-fine.

必ずしも~なくてもよい means 'not necessarily have to.' 必ずしも softens the negation from absolute to partial. ~なくてもよい is a permission pattern ('it's fine even if you don't'). ~ために expresses purpose. A useful sentence combining purpose, permission, and nuanced negation.