The Bible does not directly address God giving fallen angels an opportunity to repent. However, Scripture does share some information to help regarding this issue.
Why doesn't God give fallen angels opportunity to repent?
First, there is no reason to believe fallen angels would repent if given an opportunity. In fact, the example Jesus gives of a wandering unclean spirit reveals the opposite: "When the unclean spirit has gone out of a person, it passes through waterless places seeking rest, but finds none. Then it says, 'I will return to my house from which I came.' And when it comes, it finds the house empty, swept, and put in order. Then it goes and brings with it seven other spirits more evil than itself, and they enter and dwell there, and the last state of that person is worse than the first" (Matthew 12:43-45).
Second, no sacrifice was planned to redeem the sins of fallen angels. Scripture only teaches that Christ came to die as a sacrifice for the sins of people. Romans 5:6 makes clear, "For while we were still weak, at the right time Christ died for the ungodly."
Third, fallen angels, including Satan, were previously already in God's presence (Ezekiel 28:14). In their rebellion, they were judged with being removed from eternity with God. Instead of being given an opportunity to repent during their lifetime, angels do not die. Those "elect angels" (1 Timothy 5:21) remained faithful while the fallen angels did not.
What does it mean that there are elect angels? God apparently has chosen some angels He knew would not rebel against Him while others He knew would rebel. He has made no provision for these fallen angels to be redeemed. Humans have the opportunity to repent because of Jesus Christ. Fallen angels have no such mediator who has made a way for them to be redeemed.
In summary, fallen angels cannot repent because there is no evidence they would repent if they could, no sacrifice exists for their redemption (since Christ came for the sins of people), and God has already chosen the elect angels who would remain faithful while also knowing those fallen angels who would rebel.
All of these traits are also true of Satan himself. He is a fallen angel who was cast away from the presence of God (Isaiah 14; Ezekiel 28; Revelation 13). His time is short to cause destruction in this world, after which he will ultimately be judged with eternal separation from God in punishment (Revelation 20:9-10).
If God knew the Fall was going to happen – that Satan would rebel and Adam and Eve would sin – why did He create them?
When was the fall of Satan, and how did it happen?
Why did God allow the Satan and the demons to sin?
What are demons according to the Bible?
Does God love Satan? What does God say about Satan?
Truth about Angels