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Power Platform Community / Forums / Power Automate / Custom connector Oauth...
Power Automate
Answered

Custom connector Oauth problem CORS

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Posted on by 281

Hi experts,

I'm getting 403-error with "Invalid CORS request" in a custom connector for Zoom.:

image.png

 

The reason could be that call from client side instead of server side - so does anyone know how to adjust this?:

 

image.png

 

I'm using generic OAuth.
Not very familiar with the authentication options here, but if Azure AD would be an option, I'd be happy to try. But would need guidance on how to achieve that .

Thankful for any hints!

 

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  • Verified answer
    abm abm Profile Picture
    32,998 Most Valuable Professional on at

    Hi @Imke 

     

    I did tried creating a custom connector for Zoom. Here are the details:

     

    Here is my  Authentication type I used

     

    image.png

     

    Above I have set Refresh URL is same as Token URL

     

    Here is the method I was trying to test

     

    image.png

     

    This is my test result:

    image.png

     

    So here I have replicated your error. I did tried with different things around and tried the same in POSTMAN using OAuth2 using client Id and Client Secret. Managed to generate a Bearer token via Postman and here is the result:

     

    image.png

     

    So this confirms that CORS error is nothing to do with the credentials or headers. Next what I tried is created a Power Automate action step using the current test connection and I got a different error saying invalid token. 

     

    image.png

     

    That indicates me that something in that test connection is not quite right. So what I did next is create a new connection.

     

    image.png

     

    As you can see above I created a new connection by clicking Add new connection.

     

    Run my flow and here is the test result:

     

    image.png

     

    So try creating a new connection in your Power Automate action step. That should work as expected. I am not sure why the test failed under the custom connector. 

     

    Please let me know how it goes.

     

    Thanks

     

  • abm abm Profile Picture
    32,998 Most Valuable Professional on at

    Hi @Imke 

     

    Did you tried the below suggestion? Please let me know.

     

    Thanks

  • Imke Profile Picture
    281 on at

    Hi @abm 

    sorry, I missed your first message.

    Thank you so much, it finally worked!! At the end I had to build a new connector, but yeah - now it's working as expected in the flow itself (same error messages like you during testing…)

     

  • Imke Profile Picture
    281 on at

    Hi @abm 

    wondering if you also have an idea about the latest error-message:

    image.png

    Do I have to refresh or reset the connection in flow somewhere?

    Thanks a lot !!

     

     

     

  • Imke Profile Picture
    281 on at

    Hi @abm  

    just a quick update: I've deleted all existing connections for that custom connector and then was prompted to login again when triggering the flow again. Worked fine.

    Scheduled for every 15 mins now and its still running OK. So maybe the problem is solved now.

     

     

  • abm abm Profile Picture
    32,998 Most Valuable Professional on at

    Hi @Imke 

     

    Thanks for the update.

     

    When access tokens expire or become invalid but the application still needs to access a protected resource, the application faces the problem of getting a new access token without forcing the user to once again grant permission. To solve this problem, OAuth 2.0 introduced an artifact called a refresh token. A refresh token allows an application to obtain a new access token without prompting the user.

     

    Did you set the refresh URL. Set the link same as Token URL.

     

    image.png

     

    If all running as expected please mark the solution as expected.

     

    Thanks

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