they can offer, they may not - there is not document written rule about this.. sometimes its also based on luck.
if they don't, you can't ask because of low usage. If you spend, you can ask regardless whether they offered or not. Its upto you.
You can also utilize millennia with other gyftr purchases, if any. Or keep using on those 3 channels and improve your length of history in the bank to get offer (may or maynot possible, no guarantee!).
But if you spend atleast 1L in a year, you're on queue and get the offers. Again, not written anywhere and any guarantee.. these all based on personal and nearby people experience with the same bank.