What (if any) are you seeing when trying to open it? How to Use 7-Zip to Compress Files and Extract Files
What are you using (Windows 10/11, macOS, Linux)?
Use 7z x #BEST_15.7z -o./output_directory . Unzip One: A free alternative app on the Microsoft Store.
Download and install the free software from the official 7-Zip site. Extract: Right-click the #BEST_15.7z file. Select 7-Zip > Extract Here or Extract to "#BEST_15" . Alternative Methods
To extract or "produce" the contents of a #BEST_15.7z file, you need to use 7-Zip software or a compatible utility.