The semanage command is part of the SELinux management tools package, which is not installed by default on Red Hat Enterprise Linux (RHEL) 6/7/8 systems. To install it, you need to run the following command as root or with sudo privileges:
yum install policycoreutils-python
After the installation, you should be able to run the semanage command. If you still get the “command not found” error, try logging out and logging back in, or restarting your system to refresh the PATH environment variable.