How to resolve Laravel 401 (Unauthorized) error

api_token: this.user.api_token

         axios.post("http://foo",
         {headers: { 'Authorization' : 'Bearer '+ api_token}})
         .then(response => {
                    //action
                })

link: https://forum.vuejs.org/t/401-unauthorized-vuejs-laravel-and-passport/59770

or

       postComment() {
      axios.post('/api/posts/'+this.post.id+'/comment', {
        api_token: this.user.api_token,
        body: this.commentBox
      })

but make sure that you have "user.api_token"

Some people just assume all has been configured right out of the box; but you need to:

Follow this Laravel documentation to gain api_token for all your users. Laravel api authentication

NOTE: When you register users, if users api_token in database is still being saved as NULL, go to the users model and add api_token to fillable array

//Model/User.php
protected $fillable = [
        ...
        'api_token',
        ...
    ];

In your view layout app.blade.php create a meta for your token, just like your csrf:

//views/layout/app.blade.php   

<!-- APIToken -->
<meta name="api_token" content="{{ Auth::user()->api_token }}">

Finally in your main.js or app.js; you can include it with every sent request

//resources/app.js

window.axios.defaults.headers.common = {
    'X-CSRF-TOKEN': document.querySelector('meta[name="csrf-token"]').getAttribute('content'),
    'Authorization': 'Bearer '+ document.querySelector('meta[name="api_token"]').getAttribute('content'),
    'X-Requested-With': 'XMLHttpRequest'
  };

This works and would help someone after all I've been through; meanwhile Laravel Passport and Sanctum are better recommendation for api authentication