显示错误Laravel

Integrity constraint violation: 1452 Cannot add or update a child row.

<div class="form-group">
    <label for="exampleInputEmail1">Kode WNI</label>
    <input name="kode_wni" type="text" class="form-control" id="exampleInputEmail1" aria-describedby="emailHelp" placeholder="Masukan Kode WNI" required>
    @if (session('error'))
    <div class="alert alert-danger">{{ session('error') }}</div>
    @endif
</div>

how can I display error with this problem? only for display error message.

to show all validation errors

@if ($errors->any())
<div class="alert alert-danger">
    <ul>
        @foreach ($errors->all() as $error)
            <li>{{ $error }}</li>
        @endforeach
    </ul>
</div>
@endif

and this one just to show the error of a specific form

<input id="title" name="title" type="text" class="@error('title') is-invalid @enderror">

@error('title')
    <div class="alert alert-danger">{{ $message }}</div>
@enderror

use Try Catch block and get exception Like this,

try{

  //your code here

}catch(Exception $e){

   $message = $e->message;
   //use $message variable for message
  //set session here

}