David Chaiken

fix for issue #13722: send body for application/x-www-form-urlencoded data

2

Fix for issue #13722: verified with successful calls to /v5/oauth/token endpoints for https://github.com/pinterest/api-description @spacether ### PR checklist - [x] Read the [contribution guidelines](https://github.com/openapitools/openapi-generator/blob/master/CONTRIBUTING.md). - [x] Pull Request title clearly describes...

- [x] Have you provided a full/minimal spec to reproduce the issue? - [x] Have you validated the input using an OpenAPI validator ([example](https://apidevtools.org/swagger-parser/online/))? - [x] Have you [tested with...