Here is the quote and source:

Each time, he requested an extension to file his 1040; and each time, he made the required payment to the I.R.S. for income taxes he might owe — $1 million for 2016 and $4.2 million for 2017. But virtually all of that liability was washed away when he eventually filed, and most of the payments were rolled forward to cover potential taxes in future years.

https://www.nytimes.com/interactive/2020/09/27/us/donald-trump-taxes.html

Does that mean he paid the $1 and $4.2 in plus the $750? Was the $1 million and $4.2 million refunded to him before the $750 he paid out?

Has the tax returns’ front pages been published so we can see what line of the tax return they are talking about? Rather than interpreting explanations of the return.