Look no further! I have all the steps you'll need to get your trial balance uploaded, @finance-daenyalp.

To upload the trial balance, the file format should be .xls or .csv with a maximum of 1000 rows or 2MB​​​​​​​ file size.

Here's how:

1. Go to the Gear icon, then choose Import Data from the Tools menu.
2. Select Trial Balances.
   
   
3. Choose Download a sample file located in the Checklist before import box.
   
4. Use the sample file as your template. Prepare your trial balance data in the same format.
5. Assign an appropriate Type and Detail type.
6. AVOID the following detail types:
   • Retained Earnings
   • Accounts Receivable
   • Accounts Payable
   • Undeposited Funds.
7. If you have balances for any of these - Retained Earnings, Accounts Receivable, Accounts Payable, and Undeposited Funds in your current Trial Balance, rename them with the following information when you import:
   
8. Once it is ready, save the file.
    

Then, let's perform the import.

1. Click Choose File to upload. You will see the file has been uploaded.
2. Click Continue.
3. The Match data fields window appears where you match your data field with QuickBooks online data fields. QuickBooks maps the data automatically – fields appear with a green tick box next to it shows the mapping is successful. Click Continue.
4. In the Review Data window, mapped data fields are reviewed and error shows in case of the mismatch. 
5. Click on Error and you will find the mismatch issue. Make sure to select the correct account type.
6. Now no more error pops up. Click Import [x] records. A message box will appear if we would like to import [x] records, click Ok.
7. Import is successful and can be seen in the Import Summary step.

Once done, allocate the Accounts Payable (Creditors) and Accounts Receivable (Debtors) balances to your suppliers and customers. Then, transfer the Retained Earnings and Undeposited Funds trial balance amounts to your Retained Earnings and Undeposited Funds accounts, respectively. For the detailed steps, refer to this article: Impost trial balances. 

I'm always around to help should you need any further assistance in getting your trial balance imported in QuickBooks. Have a good one.