How to do the setting of sst at refund receipt

Welcome to the Community, @wendykerk2419.

I got here the steps so you can set up the SST in QuickBooks Online easily.

If you have your SST Registration Number, you can enter it in your account and settings. this way, the system will automatically calculate your tax in your refund receipts.

Here's how: 

1. Click on the Gear icon.
2. Choose on Account and Settings.
3. On the left panel, select Company.
4. From the Company name section, enter your SST Registration Number in the Sales and Service Tax ID field. 
5. Select Save and then Done.

Additionally, I've also added these helpful articles to give you more details about managing sales tax in QuickBooks Online: 

• Check how much sales tax you owe in QuickBooks Online
• Learn how to file your sales tax return and record your tax payment in QuickBooks Online

Please let me know if you have any other tax-related concerns. I'm just around to help. Take care always.