you can if you have all tax ID numbers available.
If you want to take the advantage of tax software. You can use a fake number to fill out the forms produced by tax software, but do not submit online, instead print a copy and white out the fake number, submit the W-7 form with your tax return, let IRS to fill the missing numbers for you when they assign ITID# for your parents.
just my idea. I really do not know it works or not.
If you can not proceed without ITID#, then you need prepare the form by yourself