SendGrid v3 API Swagger file for sending transactional templated emails from Microsoft Flow and PowerApps.
Based on the full version of the SendGrid Open API/Swagger definition
To use, you can create a new custom connection in Microsoft PowerApps and use that within Microsoft Flow.
Step 3: Upload the Swagger file
The API Key you get from SendGrid needs to be prifixed with the word "Bearer", e.g. "Bearer SG.lksfjlsiejleijclkaio032-09234ljslja39lkjdalkj". Failure to do this will cause Flow to fail with an unauthorised exception.