$event->addSubmitAction not working

Hi, I am trying to add an action to the Campaign form, through a plugin and using the following code:

public function onFormBuilder(FormBuilderEvent $event)
        $event->addSubmitAction('actions.send.lead', [
            'group'           => 'actions.form',
            'label'           => 'actions.email.form.action.sendemail.lead',
            'description'     => 'actions.email.form.action.sendemail.lead.descr',
            'formType'        => ActionEmailSendType::class,
            'formTypeOptions' => ['update_select' => 'formaction_properties_email'],
            'formTheme'       => 'MauticEmailBundle:FormTheme\EmailSendList',
            'eventName'       => FormEvents::ON_EXECUTE_SUBMIT_ACTION,
            'allowCampaignForm' => true,

My event listener shows up in the debug, but this action doesn’t load, or displays any errors in the log. Can someone help me with this?