Hi @Amin Ahcene Djaballah  To sync a newly created Salesforce task field with an Intercom automated task, you'll need to configure the field mapping for the Salesforce integration in Intercom. To do this, go to your App Store in Intercom, search for the 'Salesforce' app, and select the 'Settings' page. On the Settings page, you will find the lead/contact mapping sections where you can configure how fields from both sides map. Most default Intercom fields should be available for selection from this attribute picker. Note that once you add a mapping, data won't automatically sync until there's a change on one side of the integration or another.
However, if you're unable to find the task object mapping in Intercom, it's possible that the required fields in Salesforce are not set up correctly. Ensure that the following fields are available in the Task object in Salesforce: Description (aka Comments), CreatedById (aka Created By), ActivityDate (aka Due Date), Subject, Type, Status, Priority, and OwnerId (aka Assigned to). If any of these fields are missing or modified, you may need to adjust your Salesforce settings to make them available.

You'll find more on this in this article from our Help Center Salesforce integration troubleshooting and F.A.Q 

@bernice Everything is sych correctly but i cannot see any task custom mapping on the intercom side. 

Hi @Amin Ahcene Djaballah !

The Intercom <> Salesforce integration allows you to map Leads, Contacts, Accounts, and Cases between the two platforms. If you want to set up a sync between any other SFDC Objects your dev team will need to build that out. Intercom has Webhooks and a REST API available to help your team do this! Our Help Center has loads of articles that discuss our SFDC integration in more depth if you want to read up on what other features are available.