The Logitech Crayon will certainly work with your 9th gen iPad.
There are two versions. One with a Lightning port at the end for charging and pairing with older iPad models that still use an iPad model with Apple's Lightning port and one the uses USB-C for newer USB-C port model iPads.
The Lightning port version you need has a gray or orange color rubber cap at the top the covers/protects the Lightning port.
Tap the link below.
https://www.logitech.com/en-us/products/ipad-accessories/crayon-ipad-digital-pencil.914-000051.html
The USB-C versions have no such protective cap for the USB-C port.
The ONLY major difference between an actual Apple Pencil and the Logitech Crayon is that the Crayon has NO screen pressure sensitivity for thick to thin or light to dark markings.
The Logitech Crayon uses the same replaceable, screw on/off Apple Pencil tips.
Best of Luck to You!