I can't refresh token

I can't refresh token

I am using postman to test apis that I will be putting into  an applciaton and I am having issues getting my refresh request to work -the redirect_uri is https://www.getpostman.com/oauth2/callback (is this correct? what should it be) and what should Authorization be set to? I currently have it set to Bearer access_token

client_id={{client_id}}&
client_secret={{client_secret}}&
scope=Desk.tickets.ALL, Desk.settings.READ, Desk.basic.READ&
redirect_uri={{redirect_uri}}&
grant_type=refresh_token

    Access your files securely from anywhere

        Zoho Developer Community

            Bootcamp
            Community
            Pricing
            Webinars
            What's New
            Integrations
            Contact Support
            Contact Sales

              Zoho Survey Resources
                Features
                Survey Templates
                Integrations
                Community
                iOS Mobile Surveys
                Pricing
                Android Mobile Surveys
                Insurvey Blogs
                Insight Blogs
                Tips & Tricks





                              Latest Feature Updates


                                  Zoho Desk Resources

                                  • Desk Community Learning Series


                                  • Digest


                                  • Functions


                                  • Meetups


                                  • Kbase


                                  • Resources


                                  • Glossary


                                  • Desk Marketplace


                                  • MVP Corner


                                  • Word of the Day




                                      Zoho Marketing Automation
                                        Zoho SalesIQ Resources


                                              Manage your brands on social media
                                              Access Zoho Social

                                                Zoho Pagesense Resources


                                                    Zoho TeamInbox Resources

                                                      Zoho DataPrep Resources



                                                        Zoho CRM Plus Resources

                                                          Zoho Books Resources


                                                            Zoho Subscriptions Resources

                                                              Zoho Projects Resources


                                                                Zoho Sprints Resources


                                                                  Qntrl Resources


                                                                    Zoho Creator Resources



                                                                        Zoho Campaigns Resources


                                                                          Zoho CRM Resources

                                                                          • CRM Community Learning Series

                                                                            CRM Community Learning Series


                                                                          • Kaizen

                                                                            Kaizen

                                                                          • Functions

                                                                            Functions

                                                                          • Meetups

                                                                            Meetups

                                                                          • Kbase

                                                                            Kbase

                                                                          • Resources

                                                                            Resources

                                                                          • Digest

                                                                            Digest

                                                                          • CRM Marketplace

                                                                            CRM Marketplace

                                                                          • MVP Corner

                                                                            MVP Corner





                                                                              Design. Discuss. Deliver.

                                                                              Create visually engaging stories with Zoho Show.

                                                                              Get Started Now