Let me help you enter your purchase bills. But before that, I'd like to know if you encounter any errors while trying to create a purchase bill.
In the meantime, we can perform some basic troubleshooting steps to ensure that this isn't a browser-related issue. The initial step is to access your QBO account via incognito mode. This does not store cache files that may cause odd behaviors when running web-based programs. Below are the shortcut keys you can use:
Google Chrome: press Ctrl + Shift + N
Mozilla Firefox: press Ctrl + Shift + P
Microsoft Edge: press Ctrl + Shift + N
Safari: press Command + Shift +N
Then, enter your purchase bill again. If this works, clear the cache of your regular browser to eliminate piled-up data. If the issue persists, another supported browser or device. It might be that the current one you're using has a temporary issue with the program. The article I shared is a US version but applicable on your end.