Hi there @margaux,

Welcome to the Community! It looks like your Facebook integration is having an issue with the authentication step. Let me see what we can do about that!
This can be cause by recent updates to log in credentials 
To fix this issue we will need you to  try to remove/re-integrate. To do so please follow the instructions below:

Here are the steps:

1. Log into your Klaviyo account.

2. Navigate over to the Facebook integration page within Klaviyo.

3. Click the arrow next to Disable Integration and select Remove Integration (NOT disable).


4. Log out of Klaviyo

5. In your web browser, clear your cache and cookies. This will allow us to create a fresh connection under your Facebook page (which should have the correct admin permissions. Please ensure that you have admin permissions on your Facebook page)

6. Log into your Facebook page. Please ensure that the Facebook account which you are signed into has ADMIN permissions so that you can manage lead ads and custom audiences

7. Go to the "integrations" tab. You should not see Facebook as an enabled integration since you removed it in step 3. You can now re-add the Facebook integration.
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8. Re-add the FB integration according to this guide: How to Integrate with Facebook Advertising

Let me know if this helped!
Alex

Thank you very much! I have remove the application and it worked !!!!! thankssss