Add these imports and methods/casts to app/Models/User.php:

use Illuminate\Database\Eloquent\Relations\HasOne;

protected function casts(): array
{
    return [
        'email_verified_at' => 'datetime',
        'password' => 'hashed',
        'last_heartbeat_at' => 'datetime',
        'last_location_at' => 'datetime',
        'gps_enabled' => 'boolean',
        'tracking_enabled' => 'boolean',
        'is_online' => 'boolean',
    ];
}

public function latestLocation(): HasOne
{
    return $this->hasOne(\App\Models\LocationPoint::class)->latestOfMany('captured_at');
}

Also ensure HasApiTokens is used:

use Laravel\Sanctum\HasApiTokens;

class User extends Authenticatable
{
    use HasApiTokens, HasFactory, Notifiable;
}