When I am try to add it in Quickbooks but it says you need to upgrade to add bank with different currencies. But my Bank Account is in AED an Bank is also in AED.

Hello, usersupport4.

It looks like you're subscribed to the Simple Start edition. The reason why it asks you to upgrade is that the home currency is different. You'll want to change it to AED so you can connect your bank. I'm more than happy to show you the steps on how to fix this. 

Here's how: 

1. Click the gear icon, then select Account and settings. 
2. Go to the Advanced tab.
3. Open the Currency section.
4. Under the Home currency drop-down menu, select AED. 
5. Click Save, then Done. 

If you're working on multiple currencies, then you'll want to consider upgrading your subscription to Essentials or Plus. If you're interested in learning the basics of the Multicurrency feature, you can check this article: Turn on and use multicurrency.

Please check this article if you need help connecting your bank: Connect bank and credit card accounts to QuickBooks Online.

After getting your bank transactions into QuickBooks Online, you're ready to categorize them. 

I can give you another guide or two if you have other questions for QuickBooks Online. Just post the details of your concern here and I'll reply as soon as possible.