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The short answer is that for the official Yu-Gi-Oh! Master Duel servers.
Most sites promising "unlimited gems" are phishing scams or distribution points for malware. Risks of Using Modded APKs master duel mod apk unlimited gems
Many fake "unlimited gems" mods ask you to log in with your Konami ID or Google account. This is a direct phishing attempt. The mod developer now has your username and password. They will either steal your Master Duel account (which may have valuable cards) or try those same credentials on banking sites and social media. The short answer is that for the official Yu-Gi-Oh