The "redirect_uri_mismatch" error in OAuth2 typically occurs when the redirect URI provided during the authorization process doesn't match the one registered with the OAuth2 provider. In the context of BigCommerce, this error can occur when you are setting up OAuth2 authentication for your application.
To resolve the "redirect_uri_mismatch" error in BigCommerce OAuth2, follow these steps:
Check Registered Redirect URI: Log in to your BigCommerce Developer Account and navigate to the "Apps" section. Find the app you are trying to authenticate with and ensure that the redirect URI you are using in your application matches the one you registered with BigCommerce.
Note: The redirect URI must be an exact match, including the protocol (http/https) and port number if applicable.
Update Redirect URI in Application: If the redirect URI used in your application doesn't match the one registered with BigCommerce, update your application's code to use the correct redirect URI.
URL Encoding: Ensure that the redirect URI is properly URL-encoded, especially if it contains any query parameters or special characters.
Add Trailing Slash: In some cases, adding or removing a trailing slash at the end of the redirect URI can cause a mismatch. Make sure the trailing slash is consistent between the registered URI and the one used in your application.
Clear Cache and Cookies: If you have made changes to the redirect URI, clear your browser's cache and cookies to ensure that you are testing with the latest configuration.
Check OAuth2 Library Configuration: If you are using an OAuth2 library or package in your application to handle authentication, check its configuration to ensure that the redirect URI is set correctly.
Test in Incognito/Private Mode: Try testing the OAuth2 flow in an incognito or private browsing window to avoid any interference from previous sessions or cookies.
Contact BigCommerce Support: If the issue persists, reach out to BigCommerce support or the BigCommerce Developer Community for assistance. They can help you troubleshoot specific issues related to your BigCommerce app and its OAuth2 configuration.
By carefully checking and ensuring that the redirect URI is correctly configured and matches the one registered with BigCommerce, you should be able to resolve the "redirect_uri_mismatch" error and complete the OAuth2 authentication process successfully.