create a file named "d8lib.config.patch" in mod root and make a patch as follow

// add support to race
{
"op": "add",
"path": "/Intro/<race name>",
"value": {
"<introinternalname>": {
"name": "<intro friendly name>",
"English_description" : "<EnglishDescription>",
"French_description" : "<French Description>",
"banniere" : "<banner absolute path>",
"donjon" : "InstanceWorld:<dungeonname>:-:-",
"quete" : "<quest name>",
"introcinematique" : "<cinematics absolute path>",
"objetintropasser" : [
<item name>
]
}
}
}
// add support to intro
{
"op": "add",
"path": "/Intro/<race name>/<introinternalname>",
"value": {
"name": "<intro friendly name>",
"English_description" : "<EnglishDescription>",
"French_description" : "<French Description>",
"banniere" : "<banner absolute path>",
"donjon" : "InstanceWorld:<dungeonname>:-:-",
"quete" : "<quest name>",
"introcinematique" : "<cinematics absolute path>",
"objetintropasser" : [
<item name>
]
}
}

if you need help feel free to contact me