public String instanceUrl;
 public final string endPointUrl='https://login.salesforce.com/services/oauth2/token';
 public final String clientId ='connected app client id';
 public final string clientSecret='connected app secret key';
 public final String userName = 'target user name';
 public final String password = 'target password';
    
    public WebServiceRestotherOrg(){
        HttpRequest req = new HttpRequest();
        req.setMethod('POST');
        req.setEndpoint(endPointUrl);
        req.setBody('grant_type=password' + 
                    '&client_id='+ clientId + 
                    '&client_secret='+ clientSecret +
                    '&username=' + EncodingUtil.urlEncode(userName, 'UTF-8') + 
                    '&password=' + EncodingUtil.urlEncode(password, 'UTF-8'));
        Http h = new Http();
        Httpresponse res = h.send(req);
        string body = res.getBody();  
        
        system.debug('***** Body -- '+ body);
        
        wObj = (wrapperForHttp)Json.deserialize(body,wrapperForHttp.class);
        accessToken = wObj.access_token;
        instanceUrl = wObj.instance_url;
        system.debug('***** accessToken -- '+ accessToken + ' **** instanceUrl -- '+ instanceUrl);
              getMethod();
    }
    
    public void getMethod(){
        try{
        string queryUrl = '/services/apexrest/hello1?Accid=xyz&emailid=abc@gmail.com&companyName=test';
        HttpRequest req = new HttpRequest();
        req.setMethod('POST');
        req.setEndpoint(instanceUrl + queryUrl);
        system.debug('*** req**' +req);
        req.setHeader('Content-Length', '0');
        req.setHeader('Authorization', 'OAuth '+ accessToken);
        Http http = new Http();
        HTTPResponse res = http.send(req);
        System.debug('BODY: -- '+res.getBody());
        System.debug('-------Inserted Successfully-----');
    }

    catch(Exception e){
        system.debug('------Error Message------' +e.getMessage());
    }
        }
    
       }
    
    public class wrapperForHttp{
        String Id;
        String instance_url;
        String issued_at;
        String token_type;
        String signature;
        String access_token;
    }
}

@RestResource(urlMapping='/hello/*')
global class RestApigee {
  @HttpPost
  global static Contact helloWorld1(){
    RestRequest req = RestContext.request;
    string test = req.params.get('AccId');
    string test1 = req.params.get('emailId');
    string company = req.params.get('companyName');
    
    Contact con = new Contact();
    con.LastName = company;
    con.firstName = test;
    con.Email = test1;
    insert con;
    return con;
  }
}