I was reading a news article saying that bitcoins will not be safe once we have powerful quantum computers. Is there a good alternative way to store bitcoins safely in such a situation ?
Op the source of this information is needed for more investigation. Quantum Computer can't stop the high security of Bitcoin. There will be no additional security on Bitcoin than the highly recommend securities of Bitcoin. You can secure it offline and online with non custodial wallets. And don't keep your long term investment Bitcoins in exchange or custodial wallets.