The Messenger of Allah ﷺ said: If anyone asks Allah for martyrdom sincerely, Allah will make him reach the ranks of martyrs even if he died on his bed. (Using translation from Abū Dāʾūd 1520)
إِنَّ رَسُولَ اللَّهِ ﷺ قَالَ «مَنْ سَأَلَ اللَّهَ الشَّهَادَةَ صَادِقًا مِنْ قَلْبِهِ بَلَّغَهُ اللَّهُ مَنَازِلَ الشُّهَدَاءِ وَإِنْ مَاتَ عَلَى فِرَاشِهِ»