Yūnus

ءَآلاَنَ وَقَدْ عَصَيْتَ قَبْلُ وَكُنْتَ مِنَ الْمُفْسِدِينَ

91. “What! Now! (when facing death?) while hitherto you have rebelled and been of the mischief-makers?”

It was for this reason that Allah, addressing him, informed him that he did become a believer, while before that he used to rebel, disobey and used to commit sin; lining up alongside villains and those who were corrupt on the earth. The verse says:

“What! Now! (when facing death?) while hitherto you have rebelled and been of the mischief-makers?”

At any rate, repenting while one is dying is of no benefit. One must repent while there is still a chance of life and of being saved.