You might want to use https://www.imgtoiso.com/ to convert you .img to a .iso format.

Also i couldnt help but notice your using a hacking/pentesting distro, i have recently made a tabletop exersize hacking lab that is meant for begginers and people to retain their skills. Visit it here https://young-haxxers.github.io and you can access the github here https://github.com/young-haxxers/young-haxxers.github.io/blob/main/cryptography/MD5/Level%202/index.html