Put a shell script in your PATH named inkscape with the following content:
<span style="color:#323232;">#!/bin/sh
</span><span style="color:#323232;">
</span><span style="color:#323232;">flatpak run org.inkscape.Inkscape
</span>
Note that you can use a local folder in your home directory to house small executables and scripts like this, so you don’t have to touch your system config. I generally recommend using something like ~/.local/bin and add it to your PATH via your Shell’s RC file.
<span style="color:#323232;">flatpak run org.inkscape.Inkscape "$@"
</span>
To forward all of the arguments to the script. Note that this might be a bashism, so you might need to change your hash bang to /bin/bash as well. Double check though.
(An easy way to check if something is working as you assume is just prepend the line with echo.)