You can go into the Self Employed Worksheet and enter the business profit as a negative number. I know it can be done using the CD/downloaded version, but I am unsure about the online version.
However, there is more to it than that, and you tax return will need to be mailed if you use TurboTax. See below.
To establish that your self-employment income is subject only to foreign social security taxes and is exempt from U.S. self-employment tax, request a certificate of coverage from the appropriate agency of the foreign country. If the foreign country will not issue the certificate, you should request a statement that your income is not covered by the U.S. social security system from the U.S. Social Security Administration. Attach a photocopy of either statement to your Form 1040 each year you are exempt from U.S. self-employment tax. Also print "Exempt, see attached statement" on the line for self-employment tax.
https://www.irs.gov/individuals/international-taxpayers/self-employment-tax-for-businesses-abroad
