500 Error in Laravel with Ajax post - php

Question

I've got 6 different routes that can be chosen from an input select. Each selected route then posts to its own database.
The problem is I get a 500 error back for all of them, but on half of them, it actually posts to the database. I've gone through line-by-line, and other than the variable names, the code is identical. Here's an example of one that doesn't work at all.
submit.js
$('#submit-event').on('click', function() {
event.preventDefault()
let title = $('#title').val()
let type = $('#type').val() // for selecting which DB
let start = $('#start').data('DateTimePicker').date()
let end = $('#end').data('DateTimePicker').date()
let data = {
'_token': token,
'title': title,
'start': start,
'end': end
}
console.log(type); // logs the correct POST route
$.ajax({
method: 'POST',
url: type,
data: data,
success: function(data) {
console.log(data);
},
error: function(err) {
console.log(err)
}
});
})
routes.php
Route::post('/createmeeting', [
'uses' => 'MeetingController#postCreateMeeting',
'as' => 'createmeeting'
]);
MeetingController.php
class MeetingController extends Controller
{
// Get Meeting from DB - works
public function getMeetings()
{
$meetings = Meeting::orderBy('created_at', 'desc')->get();
return $meetings;
}
// Add new Meeting to DB - doesn't work (500 error)
public function postCreateMeeting(Request $request)
{
if (!request['_token']) {
return redirect()->route('calendar')->with(['message' => "You must be logged in"]);
}
// Save Meeting
$meeting = new Meeting();
$meeting->title = $request['title'];
$meeting->start = $request['start'];
$meeting->end = $request['end'];
if ($request->user()->meetings()->save($meeting)) {
$message = 'Event successfully added to calendar';
return redirect()->route('calendar')->with(['message' => $message]);
}
return redirect()->route('calendar')->with(['message' => $message]);
}
}
Responses to similar problems suggest a problem with the token, but I test for that here. Any idea where the mistake could be happening?