If you have not completed the rest of your return, this may be why the credit is not appearing. The energy credit is non-refundable, so if you don't have enough income tax being computed, the credit won't be generated. The maximum credit for insulation is 30% of your costs, up to $1,200. So, the credit should be $819, assuming your income tax is $819 or greater.
If you have entered all your income, and still are not getting a credit, be sure you have entered your information in the correct place in TurboTax Online:
1. Upon opening TurboTax, choose Deductions & Credits
2. Locate Your Home
3. Start/Revisit Home Energy Credits
4. On the Energy Efficient Home Improvements screen, select Yes then Continue.
5. Answer the next few questions until you get to "Did you have any of these residential energy property costs in 2024?" Insulation is listed here. Select Yes and continue.
6.In the next few screens, ensure that you answer that the home is in the US, you are the original user of the improvements, and that you expect the improvements to remain in use for 5 years, if that is true.
7. Make sure you enter the total cost and answer the questions about ownership and location of the home.
See this article for a summary of the amounts available: Energy Efficient Home Improvement Credit (EEHIC)

