this way but still it doesn't work
https://stackoverflow.com/questions/22615926/migration-cannot-add-foreign-key-constraint

Cannot add foreign key constraint..

Error is as below

SQLSTATE[HY000]: General error: 1215 Cannot add foreign key constraint (SQL: alter table `products` add constraint `products_category_id_foreign` foreign key (`category_id`) references `categories` (`id`))

  at vendor/laravel/framework/src/Illuminate/Database/Connection.php:678
    674▕         // If an exception occurs when attempting to run a query, we'll format the error
    675▕         // message to include the bindings with SQL, which will make this exception a
    676▕         // lot more helpful to the developer instead of just the database's errors.
    677▕         catch (Exception $e) {
  ➜ 678▕             throw new QueryException(
    679▕                 $query, $this->prepareBindings($bindings), $e
    680▕             );
    681▕         }
    682▕

      +9 vendor frames
  10  database/migrations/2021_01_19_074944_create_products_table.php:38
      Illuminate\Support\Facades\Facade::__callStatic("create")

      +21 vendor frames
  32  artisan:37
      Illuminate\Foundation\Console\Kernel::handle(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))

code on the migration

<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

class CreateProductsTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('products', function (Blueprint $table) {
            $table->id();
            $table->string('name');
            $table->string('slug')->unique();
            $table->string('Short_Description')->nullable();
            $table->string('description');
            $table->decimal('regular_price');
            $table->decimal('sale_price')->nullable();
            $table->string('SKU');
            $table->enum('stock_status',['instock','outstock']);
            $table->boolean('Featured')->default(false);
            $table->unsignedInteger('quantity')->default(10);
            $table->string('image')->nullable();
            $table->string('images')->nullable();
            $table->integer('category_id')->nullable()->unsigned();
            $table->foreign('category_id')->references('id')->on('categories')->onDelete('cascade');
            $table->timestamps();
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::dropIfExists('products');
    }
}