Eloquent Models

Add the MultipleDatabaseSupport trait to the base Model class (or to individual models if you prefer):

use Alberon\LaravelMultipleDatabases\Models\MultipleDatabaseSupport;

class Model extends Eloquent
{
    use MultipleDatabaseSupport;

    // ...
}

In each Eloquent model that is not in the default database, set the $table using the format <database>.<table>:

namespace App\Models\Crm;

use App\Models\Model;

class Users extends Model
{
    protected $table = 'crm.users';

    // ...
}

The database name should match the name used in the configuration, which is not necessarily the real database name.

If you have any BelongsToMany (many-to-many) relationships, add table() around the table name, like this:

public function emailAddresses()
{         
    return $this->belongsToMany(
        EmailAddress::class,
        table('crm.email_addresses'), // <-- Here
        'user_id',
        'email_address_id'
    );
}