Yahoo mail

I don't like now the updated 2017 yahoo mail because they asking you to recovery account like tap the key the problem is i dont know the last digit of my number and i don't use it anymore the number thay i used in my email address that i used. Now please help me how to back my email address i knowy emaill address and i know also my password but the problem is they asking you about tap key and the last digit number too which i dont know it i forgot please help me