Product Id Field Is Not Available in Salesforce Standard Report Types

Option 1: Create a Custom Report Type for Products

1. Follow the instructions in Create a Custom Report Type. to build a report type that includes the Product (Product2) object.
2. Click the Reports tab and select New Report.
3. Navigate to the category containing the custom report type you created.
4. Select your new custom report type and click Create.
5. In the Fields panel, search for Product.
6. Drag and drop the Product Id field onto the report.

Option 2: Create a Custom Formula Field for Product Id

1. Build a Formula Field on the Product (Product2) object and name it Product Id.
2. Set the Data Type to Text.
3. Use Id as the formula syntax. This formula returns the 18-character Salesforce record ID for each product.
4. Add this custom formula field to your standard Product reports.

Related Documentation:
Introducing Custom Formula Fields