HOW TO CLASS APEX WITH A FLOW WHEN CREATE A NEW RECORD ?

I have to call a class apex from to FLOW. 

This is my class Apex:

global class relojesCobranzaAutomatizado {     @InvocableMethod(label='Get ID cuenta factura' description='asigna el reloj cobranza de acuerdo al segmento de la cuenta factura.')

global class relojesCobranzaAutomatizado {
    @InvocableMethod(label='Get ID cuenta factura' description='asigna el reloj cobranza de acuerdo al segmento de la cuenta factura.')
    public static final String ERROR = '1';
    public static final String SUCCESS = '0';
    global class Respuesta{
        webService String resultDescription{get;set;}
        webService String result;
    global Respuesta(String resultDescription, String result){
            this.resultDescription = resultDescription;
            this.result = result;
        }
    }
    // METHOD 1.
    public static String metodoOficial(List<ID> ids){
        String segmentos;
        String ctasFact;
        String rfc;
        String razonSocial;
        String relojUno = '1';
        String relojDos = '2';
        List<CuentaFactura__c> ctaFact = [SELECT IdCuentaBRM__c, Nuevo_Segmento__c, RFC__c, Name FROM CuentaFactura__c WHERE Id IN: ids];
        for(CuentaFactura__c cf : ctaFact){
            razonSocial = cf.Name;
            rfc = cf.RFC__c;
            ctasFact = cf.IdCuentaBRM__c;
            segmentos = cf.Nuevo_Segmento__c;
        }
        if(segmentos.contains('I')){
            serviceRelojes(ctasFact, relojDos);            
        }else if(segmentos.contains('II')){
            serviceRelojes(ctasFact, relojDos);            
        }else if(segmentos.contains('III')){
            serviceRelojes(ctasFact, relojDos);
        }else if(segmentos.contains('IV')){
            serviceRelojes(ctasFact, relojUno);
        }else if(segmentos.contains('') || segmentos.contains(null)){
            serviceRelojes(ctasFact, relojDos);
        }
        return null;
    }
    // METHOD 2.
    public static Map<String, Object> serviceRelojes(String cuentaFact, String collectorId){
        Map<String, Object> datos = new Map<String, Object>();
        datos.put('msj', 'OK');
        // WEB SERVICE.
        Http http = new Http();
        HttpRequest request = new HttpRequest();
        request.setEndpoint(EndPoint__c.getValues('ChangeWatch').URL__c);
        request.setMethod('POST');
        request.setHeader('Content-Type', 'application/json;charset=UTF-8');
        request.setHeader('Accept', 'application/json');
        // SET THE BODY AS A JSON OBJECT.
        String name = 'Saleas';
        String login = '"Login" : {"user" : "2550017","password" : "M450$","ip" : "0.0.0.0"}';
        String datosCuenta = '"BRM" : {"account" : "' + cuentaFact + '", "PROGRAM_NAME" : " ' + name + '","COLLECTOR_ID" : "' + collectorId + '"}';
        request.setBody('{' + login + ',' + datosCuenta + '}');
        HttpResponse response;
        if (Test.isRunningTest()){
            Test.setMock(HttpCalloutMock.class, new DASH_DashboardRelojCobranzaAct_Mock());
            response = http.send(request);
        } else{
            response = http.send(request);
        }
        // Parse the JSON response
        if (response.getStatusCode() == 200){
            datos = (Map<String, Object>)JSON.deserializeUntyped(response.getBody());
        }else{
            datos.put('msj', 'error');
            datos.put('response', response);
        }
        return datos;
    }
}

This is my FLOW: