im trying to export my video vertailly but it wont let me
You can create a new preset for this, you have a Viewer and Export tab by default in the same window. Click the Export tab and you should be able to follow
(select .mp4 if you want the exported file to be a video)
This should be possible by just reversing the order of dimensions, width -> height when defining dimensions
Try to explain the effect you're trying to achieve if this isn't helpful.
It looks like you're new here. If you want to get involved, click one of these buttons!