How do I customize GST reports to be based on gross amounts not net amounts?

Thanks for reaching out to the Community, @jarpac.

You're referring to the amounts for each tax codes, correct? If so, this option is currently unavailable in QuickBooks Online (QBO). The GST Liability report will only display the Net and Tax amounts.

I'll pass along your suggestion to our Product Developers. They're always looking for ideas from users on how to improve QBO.

In the meantime, I recommend visiting our Blog site. This is where we share recent happenings and future developments, such as updates to newly added features.

Just in case, I'm also adding this article for future reference: Customise your reports in QuickBooks Online.

Reach out to me if you have any other issues or concerns. I'm always here to help. Have a great day!