# Illegal base64 character 28 **URL:** \ **Category:** API and Webhooks\ **Created:** [June 11, 2022, 3:07pm UTC](https://devforum.zoom.us/t/illegal-base64-character-28/70366 "2022-06-11T15:07:35Z")\ **Posts on this page:** 1\ **Showing post:** 3
**Author:** ![elisa.zoom](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/elisa.zoom/32/47836_2.png) [@elisa.zoom](https://devforum.zoom.us/u/elisa.zoom)\ **Post date:** [August 4, 2022, 2:10pm UTC](https://devforum.zoom.us/t/illegal-base64-character-28/70366/3 "2022-08-04T14:10:54Z")
Hi @kowalski.k and @regit Are you still experiencing this issue? Please refer to the following guide to make sure you are setting up your app correctly: > [@How to user Server-to-Sever OAuth app with Postman](https://devforum.zoom.us/t/how-to-user-server-to-sever-oauth-app-with-postman/70848): > > How to use our Server-to-Server OAuth with Postman? As some of you might be aware of, our JWT app is being deprecated by June 2023 and we encourage you to migrate to the newly introduced [Server-to-Server OAuth App](https://marketplace.zoom.us/docs/guides/build/server-to-server-oauth-app) That being said, here is a quick and simple guide on how to use or new app with Postman As stated in our documentation here: This new app type facilitates OAuth-authenticated requests between servers without end-user involvement. And this grant type enable your private server a… Cheers, Elisa --- _[View the full topic](https://devforum.zoom.us/t/illegal-base64-character-28/70366)._