//schema.prisma   
model Post {
  id                        String              @default(uuid())              
  name                      String                      @db.Text
  slug                      String                      @unique
  tags                      PostTags[] 
  createdAt                 DateTime             @default(now())
  updatedAt                 DateTime                  @updatedAt
}

model PostTags {
  id                        String              @default(uuid())
  title                     String
  slug                      String                      @unique
  posts                     Post[]                  
  createdAt                 DateTime             @default(now())
  updatedAt                 DateTime                  @updatedAt 
}
 //api/route.ts
import prismadb from "@/lib/prismadb";
import { auth } from "@clerk/nextjs/server";
import { NextResponse } from "next/server";
export async function POST(req: Request) {
  try {
    const { userId } = auth();
    const body = await req.json();
    const {
      name,
      slug ,
      tags,
    } = body;

    if (!userId) {
      return new NextResponse("Unauthenticated", { status: 401 });
    }

    if (!name) {
      return new NextResponse("Name is required", { status: 400 
});
    }

    if (!slug) {
      return new NextResponse("Slug is required", { status: 400 
});

    if (!tag) {
      return new NextResponse("Tag is required", { status: 400 });
    }

    const post = await prismadb.post.create({
      data: {
        name,
        slug,
        tag: {
         ...
        },
      },
    });

    return NextResponse.json(post);
  } catch (error) {
    console.log("[POST]", error);
    return new NextResponse("Internal error", { status: 500 });
  }
}

I building a Nextjs app using Prisma for my database, and the app many to many relations between the post and the tags, but I am having a problem with creating and updating a post since I don’t know how to create using m-m relation. I would greatly appreciate your help. Many thanks for considering my request.