Ahsanallahu ilaykum If someone makes kufr akbar knowingly and then makes tawba are his deeds all gone or not?

Imam Ibn Baz said: Yes, if he embraces Islam and repents, Allah will accept his repentance and preserve his previous good deeds. His deeds are only nullified if he dies upon apostasy. However, if someone mocked the religion, the Prophet ﷺ, or the Qur’an, then sincerely repented to Allah and regretted it, Allah will accept his repentance and preserve his past good deeds — as the Prophet ﷺ said to Hakim ibn Hizam: "You have accepted Islam along with whatever good you had done before."