so they mandate users to deposit first before they could withdraw?
a bit weird that we didn't see these rules and none so far that we see complaints to other sports betting sites. if the amount you have right now in the Nitro is worth more than the fee you'd be spending then go deposit. if not then just continue betting it until you can win big there. do they also require you to set up the 2fa?
In general, they are not asking such kind of deposit but you need to take a look at this
Nitro Squares Terms and Conditions
The Nitro Squares contests, both the Free Entry and Betslip Buy-in Entry contests, are open to all players of Nitrogen Sports.
New, active and inactive players from the sportsbook, poker and casino are allowed to join the contests.
Players are required to log-in to their nitrogensports.eu account before they can join the contest/s and make selection/s.
Players can enter the Nitrogen Squares contests for Free or via Betslip Buy-ins.This will be explicitly stated in each contest.
This promo is only available to good standing players of Nitrogen Sports; previously banned players are ineligible to win any prizes in this promo.
Players found to be multi-accounting or involved in any other fraudulent act for the purpose of circumventing the rules in this promo and other promos will be flagged and banned from this promo and other promos.
All users are required to make a first-time deposit and provide significant action before being able to withdraw any winnings from Nitrogen Sports poker freerolls, contests, and free bets including these Nitro Squares contests.
So I think this is okay as long as they are paying the rewards to the winners to eliminate the abusers of contests.