The slowest and most cumbersome way works. Put one piece of paper in the printer. Print a report. After the first page was printed, the printer will stop because there is no more paper in the printer.
Don't put a new sheet in. Instead, turn the printer paper over or end-to-end or however your printer requires. As soon as you put the one-side-printed page in the computer, the program will print the second page. Continue: one side, turn page over, print the other side.
Terribly slow! That is why I usually print to file when I want to print back to back. I know Word Perfect printer commands will print all even, then odd pages. I am sure Word will do the same. Read your printer manual to see how to do this. Say, you have a 50 page report. Print all the odd pages, turn them all over, print all of the even pages. (On my printer I must print all evens first, then turn, then print odds.)
By the way. I am still able to buy a full case of copy paper (5000 pages) for about $20. That means 100 pages cost about 40 cents. My time is usually worth more to me than 40 cents.