There are two elements to a back door Roth contribution:

1) The initial non-deductible Traditional IRA contribution; you enter this as you would any Traditional IRA contribution for a taxpayer.  The software will designate it as non-deductible if the taxpayer meets the various conditions, and a Form 8606 will be generated reporting this non-deductible contribution as the basis in the taxpayer's Traditional IRA;

2) The subsequent Roth conversion, which may occur in the same tax year or in the next tax year.  You receive a 1099-R form for this conversion, which you enter.  The non-deductible basis in the taxpayer's Traditional IRA (as recorded on the Form 8606)  will register such that only the earnings component of the conversion is taxable income.

That's it.