Time outside Canada under T23 NAFTA skilled worker permit

[maxritti]

Hi
I am US citizen, in Canada under NAFTA T23 skilled worker program, valid 3 years (2 more from now). How long can I travel outside Canada before the work permit becomes void?

I have seen similar questions in this forum but they all seem to cover Permanent Residents (they can be up to 3 years outside Canada before the loose PR)

Thnk you for any info
Max