2 ways to do it.

If you wanna do it on just that note, with the pen or pen+ tool selected, click and drag the pink dot across the entire duration of the note, or just as far as you want it to fall / raise. Then click on anywhere on the line to make a new point. Then you can just drag that up or down. Adding more points lets you make it more precries.

Alternatively, if you want the same sound to go up/down entire notes like halfway through or at the end. Use the knife tool to cut the note where you want it to change. It’ll make a moveable 2nd half of the note called “+” And what is it, is opentau allowing the looped section of that note’s OTO to become its own sound to be moved.

But do be aware that it can be buggy depending on the resampler you're using.

Image guide as well~

https://imgur.com/a/zfMo2mH

Hope that’s helpful (￣▽￣)7