How to adjust panel width on touch devices?

We are very happy to have panels we can toggle and adjust in their width. (That’s why we decided to build a panel for articles table of content on the right side. Left side is reserved for navigation. It’s a great step for better a11y.)

But I face an issue. I can’t find a way to adjust the width on my iPad. Is this a bug or am I not skilled enough to do it?

Regards, Simpel