Hello Team,
I have a requirement to call M3 API's through Dot Net application. While exploring, I found the GitHub library and was trying executing the sample application "DotNetWebClientOAuth2".
Now while executing the program I am able to get the access token successfully but while calling the API I am getting "Invalid_Grant" issue as below -


From the code, I can see that request owner grant is called and I am using backend user IONAPI file.

I tried the same credentials in Postman and was able to get the access token and response from M3 API.
Can somebody help me to figure out the issue or if any changes are required in the code?
Thanks,
Yogesh