I did my 2017 tax through turbo but filed extension as my refund was less than the fee amd had no other $. Can I file ot now through turbo?

You can still file it, but you still have to pay your TurboTax fee for using the software to prepare it. The fee has not gone away.  A 2017 return must be printed, signed and mailed.  it cannot be e-filed.

If you have any changes/corrections at all to make to your 2017 return, you now have to complete it using desktop software, which you must download to a full PC or Mac  (not to a mobile device).

https://ttlc.intuit.com/questions/2559403-how-do-i-finish-a-prior-year-return-that-i-started-in-turbotax-online

If you already paid for your online software you can ask customer support for a download of the desktop software.

They are available from 5 a.m. to 5 p.m. Pacific time Monday-Friday.

https://ttlc.intuit.com/questions/1899263-what-is-the-turbotax-phone-number

If you are getting a refund, there is no penalty for filing late.  If you owe tax due, then file and pay the amount due as shown on the Form 1040, but expect a bill later from the IRS for the penalty and interest you will owe.  Only the IRS will calculate this—TurboTax will not calculate it.