Hi Tuan - Hope you are well?
I just installed Membership Pro and am carrying out initial testing. I noticed that if I create a plan where the Subscription Length is set to X minutes (purely for testing where X is any value greater than zero), when I look at the plan in the front end I notice that the payment terms value shows "X Days", rather than "X Minutes".
I have checked in the Translation area and see no particular reason why this is happening. I've attached a couple of screenshots for your reference. Is this something which is fixable at this end or do you need to dig in a little bit?
all the best
Chris