It is too late to efile it. If you did it with TurboTax and just did not file it, you can do it on a desktop computer. You may have to purchase software if you did not pay for the state last year. You will need to pay for federal if you did not pay last year. You cannot efile the return, but will have to print it, sign it, attach any documents needed for filing and then mail it. It is always advisable to use a mail service that gives you a receipt when the form is delivered.
There's still time to file your Utah return and receive any refund you many have coming. As DanP0428 indicates above, you can still file your Utah return, but you can’t file it electronically.
Please see the TurboTax Help article Can I prepare and file just my state return using TurboTax? for guidance in filing last year's state return.
According to the 2020 TC-40 Utah Individual Income Tax Instructions:
To qualify for a refund or credit, you must file a return within:
three years from the original return due date (plus extensions), or
two years from the payment date.
The original return due date for your 2020 Utah return was April 15, 2021.