Is the fasting of one who stopped drinking alcohol a few days ago accepted, given the hadith, "Whoever drinks alcohol, his prayer will not be accepted for forty mornings," and he has make-up days from the previous Ramadan that coincided with the beginning of the current Ramadan?

You must take the initiative to make up the days you missed before the next Ramadan (definition), while striving to perform good deeds that expiate sins. The non-acceptance of a drunkard's prayer for forty days applies to one who has not repented. As for the one who repents, his sin is effaced, and his obedience is accepted—God willing—, for the Prophet, peace and blessings be upon him, said: "The one who repents from sin is like one who has no sin."