In "gen_license" folder.
The "gen_license_old.py" script is used for older versions. eg: Fortigate VM64 v7.4.1
The "gen_license_new.py" script is used for newer versions. eg: Fortigate VM64 v7.4.3
For older versions, executing the command python3 gen_license_old.py will generate the License.lic file. Just import the file into the system.
For newer versions, you need to unpack the init file first and then execute the python3 patcher.py init command to patch the file. After starting the system, run the python3 gen_license_new.py command and import the generated License.lic file to the system.
For newer versions, you also need to patch the flatkc file to disable rootfs checks. Please see https://wzt.ac.cn/2024/04/02/fortigate_debug_env2/ for more details.