how do decrypt topi extension files

Files with .topi extension are encrypted files, they cannot be opened, and their contents cannot be read without decryption. In some cases, when .topi files are encrypted with an offline key, these files can be decrypted. To do this, use a free program called Emsisoft STOP Djvu Ransomware Decryptor. In addition to this method, there are alternative methods to restore the content of encrypted files. They are described in the instructions link to which is given below.
How To Recover Encrypted Files (Ransomware file recovery)