Digital Rupee vs UPI: How is RBIs Digital Rupee different from UPI?

2022: The year when India's very own digital currency comes into picture. RBI has launched the first model for India’s digital rupee. Now, a digital rupee is the same as a government issued currency, only in a digital format. So the question really is, why has the government come up with the digital rupee when UPI is already so successful and popular?