新規登録の機能でError: Request failed with status code 500というエラーが出てしまう

前提・実現したいこと

vueとlaravelでtwitterのようなshareアプリを作っています。
新規登録の機能実装中に以下のようなエラーが出てしまいました。

発生している問題・エラーメッセージ

Error: Request failed with status code 500

エラーメッセージ
POST https://gentle-mesa-18924.herokuapp.com/api/register 500 (Internal Server Error)
(anonymous) @ xhr.js:184
t.exports @ xhr.js:13
t.exports @ dispatchRequest.js:52
Promise.then (async)
s.request @ Axios.js:61
r.forEach.s.<computed> @ Axios.js:86
(anonymous) @ bind.js:9
auth @ SignUp.vue:35
ne @ vue.runtime.esm.js:1854
n @ vue.runtime.esm.js:2179
Zo.i._wrapper @ vue.runtime.esm.js:6917

該当のソースコード

javascript

<script>
import HeaderAuth from "../components/HeaderAuth";
import axios from "axios";
export default {
  data() {
    return {
      name: "",
      profile: "",
      email: "",
      password: ""
    };
  },
  components: {
    HeaderAuth
  },
  methods: {
    auth() {
      axios
        .post("https://gentle-mesa-18924.herokuapp.com/api/register", {
          name: this.name,
          profile: this.profile,
          email: this.email,
          password: this.password
        })
        .then(response => {
          console.log(response);
          this.$router.replace("/");
        })
        .catch(error => {
          alert(error);
        });
    }
  }
};
</script>

php

<?php

namespace App\Http\Controllers;

use Carbon\Carbon;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Hash;

class RegisterController extends Controller
{
    public function post(Request $request) 
    {
        $now = Carbon::now();
        $hashed_password = Hash::make($request->password);
        $param = [
            "name" => $request->name,
            "email" => $request->email,
            "password" => $hashed_password,
            "profile" => $request->profile,
            "created_at" => $now,
            "updated_at" => $now
        ];
        DB::table('users')->insert($param);
        return response()->json([
            'message' => 'User created successfully',
            'data' => $param
        ], 200);    
    }
}