Welcome to the Community, Virender1. Let's go through some troubleshooting steps to resolve the issue of the Class option not showing in your Bill form. As this unusual behavior is often caused by browser problems or cached data.
Let's start by refreshing your browser to reload the page and clear minor glitches or cached data that might be causing the issue.
Next, log out of your QuickBooks Online account and sign back in. This helps refresh your session and may resolve temporary browser-related problems. Then, try creating a new Bill to check if the Class option appears.
Alternatively, you can use a private or incognito browser. This can bypass browser extensions, cookies, or cached files that may interfere. You can also switch to another supported browser, like Google Chrome, which can offer better compatibility and performance.
If the issue persists, I recommend reaching out to our Live support team for further help. They will be able to help you further with the tools and resources to investigate why the Class option isn't appearing in your Bill form.
Feel free to reach out if you have more questions. We're here to assist.