To increase the GST amount, you'll need to create journal entries that affects the sales tax accounts, user36783.
I can't provide what specific accounts would be debited and credited. Instead, I'd recommend reaching out to your accountant about this. They can give you options that will suit your company set up.
Meanwhile, you might want visit these articles to know more about GST and BAS:
If you need further help in adjusting the GST amount, you can reach out to our Customer Care Team. They can give you ideas and options to get this work.