How can I file an extension on my business taxes

If you mean a tax return for an S-corps, C-corps or multi-member partnership business---your filing deadline was March 17, 2025 so it is too late for an extension and your penalties are already adding up.

If you mean for a sole proprietor business for which you prepare a Schedule C--

Remember that an extension does not give you more time to pay.   You need to pay your tax due by April 15.   The extension only gives you more time to prepare and file your tax return forms.

https://turbotax.intuit.com/irs-tax-extensions/

https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-extension/need-file-extension-personal-state-taxes/L32Mt8ZNv_US_en_US?uid=m9a3q808

What kind of business are you trying to file an extension for?  Some filing deadlines for business tax returns has passed.

• 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.

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