If you purchased the EA, contact the coder. Most will provide the MQ4 file for a fee or as a courtesy if you prove purchase.
After analyzing hundreds of stars, forks, and issue threads, here are the most referenced projects for searches: ex4 to mq4 decompiler github verified
Some sellers claim “0/60 antivirus detection.” They achieve this by using packers or simply not having distributed malware yet . Modern malware often lies dormant for weeks. If you purchased the EA, contact the coder