Please help me, i have a small worry with my node js code. I want to assign a class to a teacher, i try to test it on postman, it does'nt work, i don't understand what is really wrong with.

here is the teacher schema

import mongoose from "mongoose";
import { Schema } from "mongoose";

const professeurSchema = new mongoose.Schema({
nom: {type: String, required: true},
email: {type: String, required: true},
motPass: {type: String, required: true},
role: {type: String, enum: ["admin","professeur"], required: true},
imageUser: {type: String},
nomClasse: {type: Schema.Types.ObjectId, ref: "Classe"},
},
{
timestamps: true
});
const Professeur = mongoose.model("Professeur", professeurSchema);
export default Professeur;

Here is the class schema

import mongoose from "mongoose";
import { Schema } from "mongoose";


const classeSchema = new mongoose.Schema({
NomClasse: {type: String, required: true, unique: true},
AnnéeScolaireDébut: {type: Date, required: true},
AnnéeScolaireFin: {type: Date, required: true},
Cycle: {type: String, required: true},
NomProf: {type: Schema.Types.ObjectId, ref: "Professeur"},
},
{
timestamps: true
}
);
 const Classe = mongoose.model("Classe", classeSchema);
 export default Classe;