Bowd virus used an online key

Unfortunately, at the moment there is no other way to decrypt files other than using the STOPDjvu decryptor. If your files are encrypted with an online key, then all that remains is to try to recover them using ShadowExplorer and PhotoRec.

STOPDjvu decryptor: https://www.myantispyware.com/2019/10/21/emsisoft-stop-djvu-ransomware-decryptor-free-way-to-decrypt-encrypted-files/
How to use ShadowExplorer and PhotoRec to recover encrypted files: https://www.myantispyware.com/2019/12/04/how-to-recover-encrypted-files-ransomware-file-recovery/