Is a takbīrat al-iḥrām required when standing to complete a missed rakʿah after inadvertently saying the taslīm in the Maghrib prayer?

If someone, after concluding their prayer, remembers shortly thereafter that they had not completed it, they should perform the remaining rak'ah. Scholars differ regarding the takbirat al-ihram (definition) (opening takbir) in this situation: some hold that it is not obligatory because the person has not exited the prayer, while others consider it obligatory, and this is the view of the Maliki school. However, if a long time has passed, then they must repeat the entire prayer.