on 2023 if we do not have K-3 schedule can we file our taxes anyways. do we do what we did last year and not check the box that the schedule K-3 is attached. if Box 21 is empty is more likely that not no foreign tax was paid

You can always do that.  The IRS doesn't require that you take every deduction that you are entitled to.  If you want to waive deductions and pay more tax they're happy to accept it.

And, in this case, it sounds like you don't have a deduction anyway so skipping it is no big deal.

@rk93