Hi there accounting-ptrpa,
It's important that all your transactions are correctly entered for your books to be well balanced. QuickBooks Online is a great tool able to help you keep track of sales and expenses so you can see the profit of your company. I can point you in the right direction to change these tax settings.
To change the accounting method for the taxes, go to the Taxes section, then Manage sales tax. Click on the Agency settings beside each tax agency to make sure they're all set to Accrual.
If you have any other questions, feel free to reach out here.