St. Paul tells us in 1 Timothy 2 to make intercessions for our fellow Christians. That intercession doesn’t stop at the veil of death. The Body of Christ is contiguous beyond it.
Saints (Rev. 5:8) in heaven offer to God the prayers of those still on earth: “And when he had taken the book, the four beasts and four [and] twenty elders fell down before the Lamb, having every one of them harps, and golden vials full of odours, which are the prayers of saints.” (Rev. 5:8) and “And another angel came and stood at the altar, having a golden censer; and there was given unto him much incense, that he should offer with the prayers of all saints upon the golden altar which was before the throne. And the smoke of the incense, with the prayers of the saints, ascended up before God out of the angel’s hand.” (Rev. 8:3-4).
If there is no asking of saints in heaven to pray for us on earth, where do they get our prayers that they offer before the altar of God? Those prayers offered in heaven must be those of the saints on earth since the saints in heaven no longer need prayers.
There is nothing in that passage of Scripture to indicate that the saints who are praying are in Heaven. It says that the beasts, the elders and the angels are in Heaven, and are offering the prayers of the saints... There is nothing I can find in Scripture to indicate that we can hear requests from others to pray for them when we are dead.