Hi jon1002,
QuickBooks Online gives you the flexibility to downgrade or upgrade your subscription when needed. I want to make sure you're able to accomplish your task so you can benefit from the robust features available in the Plus plan.
Upgrading a plan is a pretty straightforward process.
- Select Settings ⚙ then Account and settings.
- Select the Billing & Subscription menu.
- In the QuickBooks Online section, select Upgrade your plan. If you don't see it, you’re already using the plan with the most features.
- Choose a plan and select Choose plan.
- Select Get started.
If after selecting Upgrade your plan you're unable to upgrade, it could be due to a browser issue. Temporary internet files that accumulate in your browser can sometimes cause bugs in the software. To ensure your app or browser is running the program as designed, I recommend following the troubleshooting steps in this article: Clear cache and cookies to fix issues when using QuickBooks Online
Another good troubleshooting step to resolve these kinds of situations is to navigate in a private/incognito window or use a different browser compatible with QuickBooks Online. Here's an article with the list of supported browsers: System requirements for QuickBooks Online, Accountant, and QuickBooks Self-Employed
I hope this helps you get back on track! Don't hesitate if you have more questions.