If you have an existing account, you can upgrade to any Streamline 4.0 premium subscriptions. Simply do the following steps:
Log into your Streamline account at app.streamlinehq.com.
On the right-side header menu, click 'Account > Upgrade'.
Or go to 'My Account Page' and click "Upgrade to Full Access" or "Manage my account".
3. On this page, click "Update Plan".
4. Then, choose your plan and click 'Continue'.
5. On the billing page, you will see your total amount due. You can also add a user seat in the page by clicking the + (plus). Once done, click "Confirm".
6. After that, you will be taken to this page where your current plan is shown.