无法在laravel模型中使用PHP特性

我使用mailgun PHP sdk发送邮件时有一个特点，当我尝试发送邮件时，会出现以下错误：

 Trait 'App\Models\sendMailgunSdkApi' not found

这是我的折扣模型，我使用sendDiscountMail1方法中的trait

<?php
namespace App\Models;


use Illuminate\Database\Eloquent\Model;
use App\Models\DiscountCode;
use App\Models\Order;
use Carbon\Carbon;
use App\Models\Scopes\Discounts;
use Mailgun\Mailgun;
use App\Traits\SendMail;


class Discount extends Model
{


    use Discounts, sendMailgunSdkApi;

      public static function sendMail1($order)
    {

        $mailData = 
        [
            'order' => $order
        ];

        $mail = $this->sendMailgunSdkApi('emails.discounts.discount-mail-1', $mailData, 'Disfruta de tu nuevo descuento en '.config('app.name').'.', 'gabogabans@gmail.com');

        return response()->json([
            'mail' => $mail,
        ]);
    }


}

为什么它要在我的模型文件夹中寻找一个特性

我的特点是以防万一：

<?php
namespace App\Traits;


trait SendMail
{


    public function sendMailgunSdkApi($view, $mailData, $subject, $to)
    {
        $html = view($view, compact('mailData'))->render();

        $result = app(Mailgun::class)->messages()->send(config('mail.mailgun.domain'), [
            'from' => config('mail.from.name').' <'.config('mail.from.address').'>',
            'to' => $to,
            'subject' => $subject,
            'html' => $html,
        ]);

        return $result;
    }




}

使用SendMail作为特征，然后调用sendMailgunSdkApi函数

use App\Traits\SendMail;

class Discount extends Model
{
    use Discounts,SendMail;

    public static function sendMail1($order)
    {

        $mailData = 
        [
            'order' => $order
        ];

        $mail = $this->sendMailgunSdkApi('emails.discounts.discount-mail-1', $mailData, 'Disfruta de tu nuevo descuento en '.config('app.name').'.', 'gabogabans@gmail.com');

        return response()->json([
            'mail' => $mail,
        ]);
    }

}