New Facebook Page: https://www.facebook.com/OsmaniTheOttoman/
Once the prompt for the Night Market disappears, you can access your selections again by clicking on the card located in the top-right corner of your screen, right next to the store tab (so long as the Night Market is still happening, of course).
You don’t have to buy all of the skins available to you at the Night Market, but if you don’t make your purchases before it ends, you will not have another opportunity to buy those skins at the discounted price unless they appear again at the next market.
Source: https://www.distractify.com/p/when-does-the-night-market-come-back-valorant
New Facebook Page: https://www.facebook.com/OsmaniTheOttoman/
