When filling out K1 information, line 14I, I have a supplemental schedule with entries for QBI code I and REIT Div code I. How do I enter this information?

In TurboTax, you will want to enter the Box 14 information using the code ic (lower case so that you can tell it's an i and not an L or a 1).  These REIT dividends may (and probably will) qualify for the Section 199A deduction.  Enter the amount of dividends with that code as reported on your supplemental schedule, so that the portion of qualified dividends you have reported on an earlier line are designated as REIT dividends and the Section 199A deduction calculation may be applied to them.