I create INvoice NO20,create PO21 for cost 1,PO22 for cost 2,PO23 for test fee ,bill 24 for shipping fee how to associate them in Quickbook

I know how important it is to accurately record your transactions in QuickBooks, 1231 4613 1578 079. I'm here to help you out.

May I ask for more details about the transactions you'd like to link in QuickBooks Online? Are these invoices, purchase orders, and bills? This way, we'll be able to provide accurate steps to associate them.

If you'd like to add the purchase order to the bill. I'd suggest following these steps:

1. Go to the + New menu.
2. Select Bill. 
3. From the Payee ▼ drop-down menu, select the vendor. This opens a window with their open purchase orders.
4. Select Add for the correct purchase order. 
5. Once done, click on Save and close.

For more details, please see this article: Add an Accepted Purchase Order to a Transaction for your Supplier.

Once done, you can now link the bill to the invoice. Before proceeding, make sure to turn on the Billable feature. Here's how:

1. From the Gear icon, select Account and Settings.
2. Go to the Expenses tab and then click the Bills and Expenses section.
3. Place checkmark beside the Make expenses and items billable box.
4. Fill out the settings that appear below.
5. Click Save and then Done.

After that, reopen the bill and then select the Billable checkbox. Make sure to add the customer you plan to bill.

To link the billable expense to your customer's invoice, please see Step 3 in this article: Enter Billable Expenses.

As for exporting the profit detail, I'd suggest running and customising the Profit & Loss report. I'll gladly show you how:

1. Select Reports from the sidebar menu.
2. Enter "Profit and Loss By Detail" in the search bar.
3. Set the appropriate reporting period, then click the Run report button.
4. Select the Export icon, then choose Export to Excel.

Additionally, I encourage running these popular custom reports in QuickBooks Online to get awesome insights about your business.

Please let me know if you're referring to something else, 1231 4613 1578 079. It's our priority to ensure this gets sorted out.