Hey there. You should provide more information regarding your installation/system, as just stating "Touchpad not working on GNOME" isn't enough. This could be due to the fact that your touchpad's firmware was not installed for multiple reasons.

Regardless, the Team nor anyone can help you without knowing the make, model, etc. of your device.

One method that Steev previously suggested is the following:

Create a file called "/etc/dconf/db/gdm.d/06-tap-to-click" and write the following:

[org/gnome/desktop/peripherals/touchpad]
tap-to-click=true

Then run "sudo dconf update"/ Afterwards, either restart gdm, or reboot. This should probably resolve your issue.

This report has been filed against an old version of Kali. We will be closing this ticket due to inactivity.

Please could you see if you are able to replicate this issue with the latest version of Kali Linux (https://www.kali.org/get-kali/)?

If you are still facing the same problem, feel free to re-open the ticket. If you choose to do this, could you provide more information to the issue you are facing, and also give information about your setup?
For more information, please read: https://www.kali.org/docs/community/submitting-issues-kali-bug-tracker/