There are multiple ways to obtain apples without a credit card.
1- You may win them from the FMC events, which run monthly from the 5th to the 9th and have apple prizes in all four minigames for the top 3 players on the leaderboards. You can find those at Realm > Games when the event is happening.
2- You can earn them by referring new players to the game. If you get several people to sign up and be active with your referral code, you can win apples. For more information, go to Pack > Free Apples And Mushrooms.
3- You can buy them from other players with mushrooms at Realm > Barter > Search, or look for people selling them in the Sales chat or here on the forums. Keep in mind, however, that apples are pricey and usually don't go for less than 900 mushrooms a piece currently.
4- You can attempt to sell things like wolves or art you made for apples, but it's usually quite hard to sell something for apples.
5- Lastly, Eve, the site's admin, occasionally hosts competitions with apple prizes. Right now, we have the Annual Pumpkin Carving contest going on, and you can learn more about it here if you're interested:
https://wolfplaygame.com/forums.php?f=31&t=26812
Spring Month: 3 
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Flood Moon: 
