Using third-party software like bots or modded apps (YouTube "JDuel Links Bot" Guide) often violates the Konami Terms of Service .
Marginally. But Konami now tracks "action patterns." If you duel for 18 hours straight without a break, a human is not doing that. You will still get banned. Yugioh Duel Links Mod Unlimited Gems
Please be aware that using modded versions of games can pose risks, including: Using third-party software like bots or modded apps