I'm pleased to have you here in the Community, @Mattwilcockfarrier.
Allow me to share some insights about the subscription when using the QuickBooks Online Accountant (QBOA) app.
If you have an accounting firm and you're working in practice, it's just free whenever you access your QBOA app. You'll only pay for a subscription when you start adding clients. You can log in to your account to learn more more about the pricing options for your clients.
Since you want to try the app for 30 days, you can create a new account. Please take note that it will add up as a trial on the login screen. Then, you'll need to wait for one year to remove it on the screen.
For more information about QBOA, you can check out this helpful website: https://quickbooks.intuit.com/uk/accountants/online/. If you want to be a QuickBooks certified accountant, you can sign up for free training through this link: https://quickbooks.intuit.com/uk/accountants/training/.
Please update me how it goes on your end, @Mattwilcockfarrier. If you have other concerns, just drop a comment below. I'll be here to help. Take care always!