In this article, we will review how to update an expired Project Online app in Integration Hub on-premises.
Please note: An Office 365 account with a Site Collection Administrator of the root site collection permissions is required for Online App registration.
1. Go to
https://your-company-tenant.sharepoint.com/_layouts/15/appregnew.aspx where your-company-tenant is the name of your SharePoint Online tenant;
2. Click Generate for ‘Client Id’ and ‘Client Secret’.
3. Copy and save ‘Client Id’ and ‘Client Secret’.
4. Set the ‘App domain’ field to the IIS site host domain name.
5. Set the ‘Redirect URI’ field to https://integraionthub.domain.com/ConnectionProviders/ProjectOnline/AcceptAccessToken where integraionthub.domain.com is the IIS host domain name.
Please note: The 'App domain' and 'Redirect URL' values can be taken from the fourth step of the Integration Hub configurator.
6. Verify that all fields contain proper information and click Create.

Next, changing the old client ID/secret values in the configuration files for the new ones generated during app registration is required.
1. Open the configuration files:
C:\Program Files\FluentPro Software\Integration Hub\Web\web.config
C:\Program Files\FluentPro Software\Integration Hub\Service\Pip.JobProcessor.exe.config
2. Change the client ID/secret accordingly.

3. Restart FluentPro Integration Hub services and perform the iisreset.
Next, it is required to refresh the credentials for all Project Online connections. Open the integration scenarios for editing can click the Refresh button.
Only after the credentials are refreshed you can launch the integrations (click the Run Now button for your integration scenarios).