If you are doing a 'Back Door Roth'....i.e. making a non-deductible regular IRA contribution and then rolling it into a Roth...then>>>
Step 1... report the IRA contribution on the IRA Contributions WKS on line 1... just like normal
Step 2... on the 1099-R where they took it out (enter everything in the top part Line 1, line 2a, dist code), just as printed on the form...making it look taxable).
Step 3 Scroll down that worksheet to Part 7 verify distribution codes...and put a check in Box 5 (you should have an amount on line B4)