Praise be to Allah, and may peace and blessings be upon the Messenger of Allah. To proceed:
The basic principle according to Ahl al-Sunnah wa al-Jama‘ah is that it is not permissible to state with certainty that a specific person is among the people of Paradise or Hell, except for those whom Islamic revelation has explicitly testified to as such.
Are there signs that indicate a person’s final destiny?
A person may show signs of righteousness or corruption. These may be considered glad tidings or warnings, but they are not definitive proof of that person’s final destiny, because what ultimately matters is how a person’s life ends, and knowledge of this belongs to Allah alone.
The believer hopes for Allah’s mercy when obeying Him and fears His punishment when falling short. He should neither become deceived by his deeds nor despair of his Lord’s mercy.
Is there a bodily sign or revelation that determines a person’s destiny?
There is nothing in Islamic teachings indicating that a person can know their final destiny through a sign on their body or through a special personal inspiration. Whoever believes this without evidence from Islamic revelation has fallen into illusion or obsessive doubts. A person should instead focus on obeying Allah and performing righteous deeds rather than searching for matters of the unseen that Islamic revelation has not disclosed.
Conclusion
No one knows a person’s final destiny in the Hereafter except Allah Almighty. There are no definitive signs in this world proving that a particular person is among the people of Paradise or Hell. Rather, the believer hopes for the mercy of his Lord, fears His punishment, strives to obey Him, and asks Allah for a good ending.
And Allah knows best.