Create a job dsl SeedJob without UI

Question

i'm trying to automate the configuration of my jenkins under docker. I have a yml configuration file that works with the plugin Configuration as Code JCASC, which trigger a groovy script where i create my jobs. I want to create a seed job from here, IDK if i well understanded the point of a seed job but in my mind, that's a job that create other jobs. (That is what i want to do, i pass arguments to a job that reate some other jobs using the args.)

i've tried to put a new job in the step of another one:

job('Tools/SEED') {
    parameters {
        stringParam('GITHUB_NAME', null, "GitHub repository owner/repo_name (e.g.: \"Grainbox/chocolatine\")")
        stringParam('DISPLAY_NAME', null, "Display name for the job")
    }
    steps {
        dsl {
            text('job ("test") { shell("echo hello") }')
        }
    }
}

but i've got this error message:

Running as SYSTEM Building in workspace /var/jenkins_home/workspace/Tools/SEED Processing provided DSL script ERROR: script not yet approved for use Finished: FAILURE

PS: Because i want to automate the configuration, i cannot use the UI to do it, i need my docker to be working right after the first time it has been compiled.

Any idea on how to do it?