What is the ruling on someone who caught up with the Imam for one takbir of the funeral prayer and missed three takbirs, and what is required of him to do?

Whoever misses a part of the Janazah prayer should complete what they missed and say three takbirat (Allahu Akbar) as a makeup before the Janazah is lifted, then give the taslim. What they caught with the Imam is considered the beginning of their prayer. After the second takbirah, it is sufficient for them to say: "O Allah, bless Muhammad." After the third, they say: "O Allah, forgive him," then give the taslim after the fourth.