Q:

Sheikh what if a person utters words of kufr and shirk and sincerely says the shahadah but does not do tawbah from those words and dies in that state what will be his fate on yawmul qiyamah

A:

It is important for anyone guilty of major sins to return to Allah in repentance:

How shall God guide a people who have disbelieved after having believed, having borne witness that the Messenger is true, and the clear proofs having come to them? And God guides not wrongdoing people. They are those whose recompense is that upon them shall be the curse of God, the angels, and mankind all together, abiding therein; the punishment shall not be lightened for them, nor shall they be granted respite, except those who repent after that, and make amends, for truly God is Forgiving, Merciful. Truly those who disbelieve after having believed, then increase in disbelief, their repentance shall not be accepted, and they are the ones who are astray. (Quran 3:86-90)

So, such a person ought to repent and reaffirm the faith in Islam.

Almighty Allah knows best.