Is it ok if we make appointment and doesn't show up?

[ssg10]

I am trying to get to Canada now using automatic revalidation, but just in case something is wrong i want to make appointment at nvars.com for h1b visa stamping. If i don't show up at appointment, is it ok or i'll be in blacklist or something?

anybody knows?

also, does anyone know contact number for the border agent office at washington state and british columbia border?

Thanks