It wasnarrated that Ibn 'Abbas said:
"The Messenger of Allah (ﷺ)said: 'Whoever forgets to send peace and blessings upon me, then hehas missed the road to Paradise.'" (PT)
English reference (PT): Vol. 1, Book 5, Hadith 908 (PT)
Arabic reference (PT): Book 5, Hadith 961 (PT)