No, you cannot skip those 2 years. You are required to file based on the IRS filing requirements (please read the blue links) -not based on whether you have a refund or taxes owed... You can still file with TurboTax, but you will have download prior year software to do so, you can no longer do it online for prior years. You will also have to print and mail your tax returns.
This link here provides more details on filing if you don't owe tax.
Thank you for the clarification. Yes - you can skip those two years and not file since you didn't have to file per the IRS rules. Just resume with your 2018 tax return, if you are required to file.
You can still file. When going through the TurboTax interview, you will have an option to indicate that you didn't' file last year. Please read What do I put for my AGI if I didn't file last season for details.