The way I know is to purchase Amazon Gift Card using SBI Cashback card. This will give you 5% cashback. Add this Gift card to your Amazon Pay balance. Then use this Amazon Pay balance to pay your LIC premium. I think direct payment on LIC website using SBI cashabck will earn 1% only. I have not tried direct payment.
It is not about the demand, It has been the same since launch...SBI put Gyftr, Zingoy etc on suspicious website list (don't know why), so, transactions get blocked most of the time, it just depends on your luck. For some ti will never work, for some it works 1 out of 10 times. Also. getting card unblocked though CC (if you don't receive the IVR call) is a pain