TurboTax does not calculate the MAG for the purpose of a Roth IRA contribution before you enter a Roth IRA contribution. Once you make that entry, TurboTax prepares the Roth IRA Contribution Limit Worksheet which will have your MAGI on line 1.
Since you appear to be using the online version of TurboTax, you won't be able to view that worksheet until you pay for TurboTax (if necessary to pay to file), but when you go through the Roth IRA contribution section TurboTax will inform you if the Roth IRA contribution you entered exceeds the limit. If you subsequently make other changes to your tax return that might change your MAGI you'll need to go back through the Roth IRA contribution section to see if the amount of your excess contribution has changed. If you go through the TurboTax step-by-step process in order, all of the information needed to determine your MAGI will already be present when you go through the Roth IRA contribution section. You'll still want to print and examine your tax return before filing to see if you have any excess-contribution penalty on Form 5329 Part IV.
You can determine your MAGI yourself:
https://www.irs.gov/publications/p590a#en_US_2022_publink1000230985
