Why API subscription is linked to Margin?

One of the sometime frustrating issue I have seen is that Dhan API subscription is deducted from margin, for instance this month due to SEBI mandate Dhan credited back the balance from Dhan account to bank account, and before I could make the transfer again the API subscription expired.

Adding to it I made transfer back to account in evening on Friday which would will not be accepted by Dhan API subscription before Tuesday as Monday is public holiday. Now with this I am stuck without API access, 3 days which I could have used to develop and test some strategy over the weekend would go to waste as I won’t be able to get Dhan API subscription, why can’t one pay the fee directly through UPI for instant access, why it has to be tied to margin account only.