We have all wronged others one time or another. Some we remember, some we do not and others we do not even realise. We do not want to lose our rewards and certainly do not want to take the sins of those we have wronged.
Prophet Muhammad ﷺ (may Allah send Blessings and Peace upon him) once asked his companions:
“Do you know who is the bankrupt (poor)? They (the Companions of the Prophet ﷺ) said: “A bankrupt (poor) man amongst us is one who has neither dirham with him nor wealth.” He (the Prophet ﷺ) said: “Indeed, the bankrupt (poor) of my Ummah would be he who would come on the Day of Resurrection with prayers, fasts and zakat but (he would find himself bankrupt on that day as he would have exhausted his rewards of good deeds) since he hurled abuses upon others, brought calumny against others and unlawfully consumed the wealth of others and shed the blood of others and beat others, and his rewards of good deeds would be credited to the account of one (who suffered at his hand). And if his good deeds fall short to clear the account, then the sins of those whom he has wronged would be entered in (his account) and he would be thrown in the Hell-Fire.” [Sahih Muslim (2581)]
So if you have cursed anyone, hurt anyone’s feelings wrongfully or backbitten anyone and you regret it but cannot fix it or cannot remember who you have wronged, then there are many Sunnah du‘aas (supplication) in different variations you can recite to make up for it.
Download the PDF file from the link below to learn the du‘aas and recite them in your prayer and before you go to sleep everyday. You can choose to recite whichever listed in the PDF file that suits your situation: https://tinyurl.com/7wer22tv
May Allah forgive all of our sins and grant us entry into Jannatul-Firdaus. Aameen.