问此路由不支持GET方法。支持方法: POST。当我想输入数据时

EN

`Access to XMLHttpRequest at 'http://localhost/lat_laravel-vue1/public/api/siswa/tambahsiswa' from origin 'http://localhost:8080' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource.` 

"The GET method is not supported for this route. Supported methods: POST.". 

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;
use App\siswaModel;
use Illuminate\Support\Facades\Validator;

header('Access-Control-Allow-Origin: *');
class siswaController extends Controller
{
    public function simpan(Request $req)
        {
            $validator = Validator::make($req->all(), [
                'nama_siswa' => 'required',
                'tanggal_lahir' => 'required',
                'gender' => 'required',
                'id_kelas' => 'required'
            ]);
            if ($validator->fails()) {
                return Response()->json($validator->errors());
            }
            $simpan = siswaModel::create([
                'nama_siswa' => $req->nama_siswa,
                'tanggal_lahir' => $req->tanggal_lahir,
                'gender' => $req->gender,
                'id_kelas' => $req->id_kelas,
                'alamat' => $req->alamat
            ]);
            if ($simpan) {
                $data['status'] = true;
                $data['message'] = "Sukses Menambahkan Siswa";
            } else {
                $data['status'] = false;
                $data['message'] = "Gagal Menambahkan Siswa";
            }
            return $data;
        }
    }

Route::post('/tambahsiswa', 'siswaController@simpan');

    <div class="container">
        Nama Siswa
        <input type="text" name="nama_siswa" v-model="nama_siswa" class="form-control">
        <br>

        Tanggal Lahir
        <input type="date" name="tanggal_lahir" v-model="tanggal_lahir" class="form-control">
        <br>

        Gender
        <select name="gender" v-model="gender" class="form-control">
            <option></option>
            <option v-for="gender in listgender" :key="gender.key" value="{{gender.key}}">{{gender.val}}</option>
        </select>
        <br>

        Alamat
        <textarea rows="4" class="form-control" v-model="alamat" name="alamat"></textarea>
        <br>

        Kelas
        <select name="kelas" v-model="kelas" class="form-control">
            <option></option>
            <option v-for="kelas in listkelas" :key="kelas.id" value="{{kelas.id}}">{{kelas.nama_kelas}}</option>
        </select>
        <br>

        <button class="btn btn-primary" @click="simpansiswa()">Simpan</button>
    </div>
</template>
<script>
export default {
    name: "Tambahsiswa",
    data() {
        return {
            'listgender': [
                { key: 'L', val: 'Laki-laki' },
                { key: 'P', val: 'Perempuan' }
            ],
            listkelas: [],
            nama_siswa: '',
            tanggal_lahir: '',
            gender: '',
            alamat: '',
            kelas: '',
        }
    },
    methods: {
        getkelas:function() {
            this.axios.get('http://localhost/lat_laravel-vue1/public/api/getkelas').then((result) => {
                this.listkelas = result.data
            })
        },
        simpansiswa:function() {
            var datasiswa = {
                nama_siswa: this.nama_siswa,
                tanggal_lahir: this.tanggal_lahir,
                gender: this.gender,
                alamat: this.alamat,
                id_kelas: this.kelas
            }
            
            this.axios.post('http://localhost/lat_laravel-vue1/public/api/siswa/tambahsiswa', datasiswa).then((result) => {
                console.log(result)
            })
        }
    },
    mounted(){
        this.getkelas();
    }
}
</script>```