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Create mobile authorization code API is not working?
Reader SDK isn’t available in sandbox. In your logged out state you in sandbox. In your logged in state you are in production which is supported. If you switch to production while logged out it will work as expected. 
I am using the production details only after logout.
How should I implement this API in my app, if this doesn’t work?
I have to enter the authorization code manually or scan a QR code to authorize your document based on step 3.
Alternatively, I can use an API to get the authorization code.
I’m not sure I understand your question. When you are logged in you can select Production in the top middle to make a production call to the CreateMobileAuthorizationCode go get the code with the API which is supported.
Please let me know how should I implement this in my app?
With Reader SDK and OAuth you will need to first have your customer authorize the your application with the correct scope. Once they have authorized your application you can then call CreateMobileAuthorizationCode with the OAuth access token that was returned when your customer authorized your application. This will allow them to connect a reader an process payments with your application.
Did you find any solution. I am also having same Issue.
Hi @Luther8399
I did not get any solution yet.
What errors are you running into now? Were you able to use the above to successfully OAuth and create the mobile authorization code?