Softaculous has backup and restore features, but their have a custom format for doing backups. So you can load a Softaculous backup into Softaculous to restore it, but not import backups from other systems.
I also don’t know exactly how well that backup feature works here. We have a more or less custom implementation of Softaculous and I don’t know if all Softaculous features work properly.
What did you use to create your backup? If you just have an archive of the files and a .sql dump, I would suggest following this guide instead: