One can choose a reliable third party application which can perform the task to unlock 7z file with safety. So you can give a try to SysInspire
which is designed with the purpose to accomplish this task in simple way. This tool does not require human interference for performance. Choose the file from the local file and restore password with any one of the provided recovery methods such as Brute Force Attack, Mask Attack, and Dictionary Attack. Password in any language with any number of characters can be restored easily. A free demo version is also offered to all with compatibility with all editions of Microsoft Windows OS and 7z/7zip file.
Read More:- https://www.sysinspire.com/7z-password-recovery-software/