TwilioService.java

public class TwilioService {

    @InvocableMethod(label='Send Verification SMS' description='Send Verification SMS' category='Login' callout=true)
    public static List<TwilioService.InputWrapper> run(List<TwilioService.InputWrapper> code){
        sendSMS(code.get(0));
        return code;
    }
    
    private static void sendSMS(TwilioService.InputWrapper input){
        
        HttpRequest httpReq = new HttpRequest();
        httpReq.setEndpoint('callout:Twilio'+'/2010-04-01/Accounts/'+SYSTEM.LABEL.TWILIOACCOUNTSID+'/Messages.json');
        
        httpReq.setMethod('POST');
        httpReq.setHeader('Content-Type', 'application/x-www-form-urlencoded');
        
        String body = 'From='+EncodingUtil.urlEncode(System.Label.TWILIO_PHONE, 'UTF-8')+'&Body='
            		  +EncodingUtil.urlEncode('Salesforce has requested you to verify your idendity. Use below code to verify '+input.code, 'UTF-8')
            		  +'&To='+EncodingUtil.urlEncode('+91'+input.phone, 'UTF-8');
        httpReq.setBody(body);
        HttpResponse response = (new Http() ).send(httpReq);
        
        System.debug(' response '+response.getBody() );
        if(response.getStatusCode() == 200){
            
        }else{
            
        }
    }
    public class InputWrapper{
        @InvocableVariable(label='Verification Code' required=false)
        public String code;
        @InvocableVariable(label='Salesforce User Contact No' required=false)
        public String phone;
        @InvocableVariable(label='Country Code with +' required=false)
        public String countryCode;
    }
}