If we don't need OTP / Security code while login what needs to be done please suggest.

There are ways to perform so you don't need to enter a code. And I’m here to provide those steps for you, @usersunil-n.

You'll want to turn off the opt-in two-step verification on your profile so you will no longer have to enter code upon logging in into QuickBooks.

Here's how:

1. Go to Sign in to your QuickBooks Online account.
2. From the left menu, select Sign In & Security.
3. Refer to the Two-step verification section and turn it off.
4. Follow the onscreen instructions to confirm.

Once this feature is disabled, you will only be asked to verify your account, when you log in from a new device, a new browser, or when you clear or reset your current browser's cached data.

You can also add Intuit or QuickBooks site as one of the trusted websites of your browser. That way, you won't be required to enter codes every time you access your account. To do so:

1. Select the Customize and control ⋮ icon.
2. Tap Settings.
3. Hit Advanced.
   
4. Under Privacy and Settings, select Site Settings.
   
5. Select Cookies.
   
6. In the Allow section, select Add.
7. Enter *intuit.com, then select Add to save.
   

Additionally, I've included an article that can help you change your email address, user ID, or password in QuickBooks Online. This can help manage and secure your account.

Please know you can always reach me here for all of your QuickBooks needs. Thanks for coming to the Community.