It wasnarrated from Anas bin Malik that the Prophet (ﷺ) said:
"There isnothing standing between a person and Shirk (polytheism)exceptleaving the prayer, so if he leaves it he has committed Shirk." (AR)
English reference (AR): Vol. 1, Book 5, Hadith 1080 (AR)
Arabic reference (AR): Book 5, Hadith 1133 (AR)