Since .7z is a compressed archive format, you cannot read the text inside without first decompressing or "unzipping" the file.
: Developers often use such names for temporary ZIP or 7z backups. J&M123.7z
You can use 7-Zip on any computer, including a computer in a commercial organization. You don't need to register or pay for 7-Zip. 7z Format - 7-Zip 18 Documentation J&M123.7z