Do you have to submit a separate extension for your LLCor is it included within your extension?

If your LLC is a single member LLC or you share the LLC with your spouse, you don't file a separate extension because you report your LLC profits or losses on your Schedule C.

If your LLC is  is: a Partnerships (including LLCs), C Corps (Form 1120), and S Corps (Form 1120S),

the extension time has passed.  All you can do is file your business return late.

• March 17, 2025 - Tax returns are due for some business types (partnerships and S corporations). Businesses taxed as partnerships (including multi-member LLCs) and S corporations need to file Form 1065 or Form 1120-S, respectively, by March 17, 2025, if they are a calendar year business. If your business uses a fiscal year, you need to file your tax return by the 15th day of the third month following the close of your tax year. For example, if your business uses an April 1 to March 31 tax year, your business tax return would be due June 16, 2025 instead of March 17, 2025.
• April 15, 2025 - Taxes for C corporations are due. Businesses organized as a C corporation need to file Form 1120 by April 15, 2025, if they are a calendar year business. If your business uses a fiscal year, you need to file your tax return by the 15th day of the fourth month following the close of your tax year. For example, if your business uses an April 1 to March 31 tax year, your business tax return would be due July 15 instead of in April.
• September 15, 2025 - Deadline for extended partnership and S corporation returns
• October 15, 2025 - Deadline for extended C corporation returns

Refer to the TurboTax article  Every Tax Deadline You Need To Know for more information.