I connected my credit card account and not all of the transactions came over. How do I fix this?

I've got the steps you need how to get your missing transactions into QuickBooks Online, sugarworks.

You'll have to upload them manually into QBO. I'll guide you on how to accomplish the tasks.

Before performing this process, you’ll have to know the date of the oldest existing entry recorded in the account to prevent duplicates. Then check with your Financial Institution (FI) to see if you can get the transactions for the period mentioned above.

If they can provide the bank data, download them using a CSV file. Once you have all the information handy, follow the steps below to import them.

1. In QuickBooks Online, navigate to the Transactions or Banking menu on the left panel.
2. Head to the Banking tab and click the Blue tile icon to select the account you’re working on.
3. Then click the Link account drop-down and choose Upload from file to open the Import bank Transactions screen.
4. Go to the Manually upload your transactions section and tap the select files link.
5. Select Browse and pick the file you downloaded from your Financial Institution (FI).
6. Tap Next and press the QuickBooks account drop-down to the account you want to upload the transactions.
7. Click Next and follow the onscreen steps to complete the import process.

For more information, check this article: Manually upload transactions into QBO:

Moreover, here are links that resolve banking issues and accepted files:

CSV file format and steps to classify transactions.

• Fix bank upload errors 
• Format CSV files in Excel to get bank transactions into QuickBooks
• Categorize and match online bank transactions 

Let me know if you have other concerns or questions. I'll be around to help you anytime. Take care!

@sugarworks 

Another option, utilize MT Online as a workaround. It is designed to import into any bank or credit card in QuickBooks Online, so there is no specific setting needed. 

https://www.moneythumb.com/?ref=110