I can connect thru app but not thru web

Good to know that you can connect through the QuickBooks Online app, @ousmanesjibrilba.

Let's get your browser up and running by doing some fundamental troubleshooting steps. This way, you can manage your account through the web as soon as possible. 
 

To ensure we're on the same page, are you trying to connect your bank to QuickBooks Online? If so and unable to connect within the web, I'd recommend accessing your account through incognito. These browsers won't save any cache history. A browser full of cache and temp files can cause unforeseen behaviors. 

You may use the shortcut keys below: 

• Ctrl + Shift + N (Google Chrome)
• Ctrl + Shift + P (Firefox)
• Control + Option + P (Safari)
• Ctrl + Shift + P (Microsoft Edge)

From there, re-connect the bank to verify if it's already performing adequately. If that works, you'll want to clear the cache of your regular browser. That'll remove previously stored browsing data that might have caused the issue. Using another supported browser is a good alternative too. 

Once connected, QuickBooks automatically downloads transactions. Please click the Update button to refresh and get the latest transactions. Then categorise and reconcile them whenever you're ready. 

In case you've encountered some problems in downloading or see errors, check out these helpful articles. 

• Fix bank upload errors in QuickBooks Online
• What to do if you get a bank error or can't download transactions

Notify me if you have additional questions about your account. I'm willing to answer them. Keep safe.