Is performing dhikr a specific number of times, as mentioned in unapproved books, considered an innovation (bid'ah)? And what are the reliable books for daily dhikr?

Authentic supplications have been narrated from the Prophet, peace and blessings be upon him, which are to be repeated 100 times a day and night, such as:

"There is no god but Allah, alone, without partner. To Him belongs all sovereignty and all praise, and He is over all things competent." Whoever says it 100 times, it is equivalent to freeing ten slaves, 100 good deeds are written for him, 100 bad deeds are erased from him, and it is a protection for him from Satan on that day until evening. "Glory be to Allah and with His praise." Whoever says it 100 times, his sins will be forgiven, even if they are like the foam of the sea.

Among the reliable books on supplications and remembrances are:

1. ʿAmal al-Yawm wa al-Laylah by al-Nasa'i. 2. Al-Adhkar by Imam al-Nawawi. 3. Al-Sahih al-Musnad min Adhkar al-Yawm wa al-Laylah. 4. Sahih al-Kalim al-Tayyib by al-Albani. 5. Hisn al-Muslim by al-Qahtani.