What happened if NTS is expired?

Hi everyone,

I have an NTS for [AUD] that will expire in 2 weeks. The reason I don't want to pay the fees is that I want to stay focused on FAR until I pass as i failed recently. I don't want to complicate myself with other exams. What will happen if I don’t pay? Can I reissue an NTS when I’m ready for AUD later?

Note: this question is not for me