It's nice to see you here, siddhi_mehta. 

 I'm here to make sure you'll be able to set up taxes correctly in QuickBooks Online (QBO). 

You'll have to tick the box for Charge Sales Tax to allocate the tax rate to an expense. Let me guide you on how: 

1. Go to the Gear icon. 

2. Select the Account and Settings under Your Company. 

3. Choose  Expenses from the left panel.

4. Click the pencil icon under Bill and Expenses.

5. Tick the box for Charge sales tax. 

I've added this article for additional reference about setting up taxes: Set up and use automated sales tax in QuickBooks Online.

 Find out more about sales tax reports including the Sales tax liability in QBO: Sales tax in QuickBooks Online. 

I'll be around if you have other questions or concerns about setting up taxes in QBO. Click the Reply button to leave a comment. I'll pop right back in to answer them for you. Enjoy your day