Writing a post method !! of course for Egnyte Integration

Method to get the files under one folder

public string emailFile(){
                
                if(wrapPdfLinksList!=null && wrapPdfLinksList.size()>0 ){
                        list<string> selectedFiles = new list<string>();
                        for(wrapPdfLinks w :wrapPdfLinksList){
                                if(w.check)
                                selectedFiles.add(w.pdfLink);
                        }
                        for(string thefolder :selectedFiles){
                                
                                // Create a new http object to send the request object 
                                string accessibility = 'anyone';
                                boolean send_email = false;
                                string path =thefolder;
                                boolean notify = false;
                                string recipients;
                                //End of creating the variables
                                
                                /*//to get quote num
                                temp1 = thefolder.split('/');
                                if(temp1.size()>5){
                                    system.debug('***** temp1-- '+temp1);
                                        if(temp1[4] != null)
                                            quoteNo = temp1[4];
                                }   
                                //End to get Quote Number*/
                                
                                //to get the receipent of the Quote
                                list<Quotes__c> receipientList = new list<Quotes__c>([SELECT Email__c from Quotes__c WHERE Name =: quoteNo Limit 1]);   
                                system.debug('UUUUUUUUUU'+receipientList);
                                
                                if(receipientList != null){ 
                                    for(Quotes__c a :receipientList){
                                        recipients = a.Email__c;
                                        system.debug('DDDDDDDDDD'+recipients);
                                    }
                                }
                                //end to get the receipent of the Quote
                                
                                
                                HttpRequest req = new HttpRequest();
                                req.setEndpoint('https://constructionspecialties.egnyte.com/pubapi/v1/links');
                                req.setMethod('POST');
                                 
                                list<eToken__c> sToken = new list<eToken__c>([Select Token__c From eToken__c where name =: UserInfo.getUserEmail()]); 
                                system.debug('***sToken**'+sToken);
                                 
                                req.setHeader('Authorization', 'Bearer '+sToken[0].Token__c);
                                req.setHeader('Content-Type','application/json');
                                                                
                                string reqBody = '{"accessibility":"'+accessibility+'","send_email":"'+send_email+'","type":"file","path":"'+path+'","notify":"'+notify+'","link_to_current":"true","recipients":["'+recipients+'"]}';
                                req.setBody(reqBody);
                                
                                Http http = new Http();
                                HTTPResponse res = http.send(req);
                                system.debug('reqBody'+reqBody);
                                System.debug(res);
                                system.debug('***** response---'+res.getStatusCode());
                                system.debug('***** to string---'+res.getbody());
                                //fileURL = res.getbody();
                                string theResponse = res.getbody();
                                
                                string afterUrl = theResponse.subStringAfter('"url":"');
                                 system.debug('***** afterUrl---'+afterUrl);
                                string theUrl = afterUrl.subStringBefore('","recipients":');
                                system.debug('***** theUrl---'+theUrl);
                                fileURL = theUrl;
                        }
                
                } 
         
         String url = '/_ui/core/email/author/EmailAuthor?p7=The%20files%20'+fileURL; 
         pageReference pr = new PageReference(url);
   pr.setRedirect(true);
      return url;
         }