Most appropriate way to switch classes of active Apis in a system?

Question

Next, In this application there is an SMS sending module that has several different Apis, all follow the same basic standard, implement the required methods of the SMS interface, something like this:

interface Sms {

    function setNumber();

    function setMessage();

    function Send();
}

class smsEmpresa1 implements Sms () {
    ...
}

class smsEmpresa2 implements Sms () {
    ...
}

And in the controller, the active API is called through a value saved to the database:

switch ($sms_ativo) {

        case '1':
            $sms = new smsEmpresa1;
            break;

            case '2':
            $sms = new smsEmpresa2;
            break;
    }

    $sms->setNumber('xxxx');
    $sms->setMessage('yyyy');
    $sms->Send();

But that way there is no standardization, the API number is set manually, and every time you create a new class you need to add on the switch, which would be the most appropriate way to do this?