https://laravel.com/docs/5.8/routing#form-method-spoofing
HTML forms do not support PUT, PATCH or DELETE actions. So, when defining PUT, PATCH or DELETE routes that are called from an HTML form, you will need to add a hidden _method field to the form. The value sent with the _method field will be used as the HTTP request method:
<form action="/foo/bar" method="POST">
<input type="hidden" name="_method" value="PUT">
<input type="hidden" name="_token" value="{{ csrf_token() }}">
</form>