Question about liquidation and margin call.

I couldn’t find any answers even from support so maybe I can get answer from someone here who has been through a margin call before. Are you asked to re-add/top up the amount until it reaches to your initial collateral when you took the loan? For example. I took a loan 25k for a collateral of 100k (25% LTV). At 65% I am margin called and been asked for collateral top up. Do I top up $61,538 to match back 100k (initial collateral) or I just have to top up any amount as long as it is above the margin call? Tq

Edit: scary. A lot of scammers in my chat box. 😱