Call to undefined method App\Models\User::createSetupIntent()

I am trying to implement subscriptions with stripe integration using cashier packages in my Laravel application. I am facing this error whenever I select a plan.

My PlanController.php file code is as followed

<?php
  
namespace App\Http\Controllers;
  
use Illuminate\Http\Request;
use App\Models\Plan;


class PlanController extends Controller
{
    /**
     * Write code on Method
     *
     * @return response()
     */
    public function index()
    {
        $plans = Plan::get();
  
        return view("plans", compact("plans"));
    }  
  
    /**
     * Write code on Method
     *
     * @return response()
     */
    public function show(Plan $plan, Request $request)
    {
        $intent = auth()->user()->createSetupIntent();
  
        return view("subscription", compact("plan", "intent"));
    }
    /**
     * Write code on Method
     *
     * @return response()
     */
    public function subscription(Request $request)
    {
        $plan = Plan::find($request->plan);
  
        $subscription = $request->user()->newSubscription($request->plan, $plan->stripe_plan)
                        ->create($request->token);
  
        return view("subscription_success");
    }
}

After searching for solutions online I am still stuck at the same problem. Kindly help.

Some other models that might help you in finding solution are as followed:

Plan.php The model file for plans

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;

class plan extends Model
{
    use HasFactory;
    protected $fillable = [
        'name',
        'slug',
        'stripe_plan',
        'price',
        'description',
    ];
  
    /**
     * Write code on Method
     *
     * @return response()
     */
    public function getRouteKeyName()
    {
        return 'slug';
    }
}

Model file for users User.php

<?php

namespace App\Models;

// use Illuminate\Contracts\Auth\MustVerifyEmail;
use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Foundation\Auth\User as Authenticatable;
use Illuminate\Notifications\Notifiable;
use Laravel\Sanctum\HasApiTokens;
use Laravel\Cashier\Billable;

class User extends Authenticatable
{
    use HasApiTokens, HasFactory, Notifiable;

    /**
     * The attributes that are mass assignable.
     *
     * @var array<int, string>
     */
    protected $fillable = [
        'name',
        'email',
        'password',
        'role',
        'plan',
        'created_by',
        'status',
    ];

    /**
     * The attributes that should be hidden for serialization.
     *
     * @var array<int, string>
     */
    protected $hidden = [
        'password',
        'remember_token',
    ];

    /**
     * The attributes that should be cast.
     *
     * @var array<string, string>
     */
    protected $casts = [
        'email_verified_at' => 'datetime',
    ];
}

Add the Billable trait from Laravel Cashier to your User model.

use Laravel\Cashier\Billable;
 
class User extends Authenticatable
{
    use Billable, HasApiTokens, HasFactory, Notifiable;
}