How can I extend my tax return when filing from abroad? Am not military service but should be within the period can extend, currently not giving me that option.

You can file an extension thru TT now  ONLY   if you are military ...  https://turbotax.intuit.com/irs-tax-extensions/

If not then you will need to mail in the form. https://www.irs.gov/pub/irs-pdf/f4868.pdf

Line 8—Out of the Country.  If you are out of the country on the regular due date of your return, check the box on line 8.