Due to the technical constraints of Google's authentication provider, it is not possible to be part of multiple institutions when you are authenticated via Google. In order to be part of multiple institutions when you are using Google authentication, you need to sign up with a different email and link your accounts instead. Here's how to do this:
Start by logging out of Eduflow with your Google account. You can do that by clicking this link.
Now, sign up to Eduflow again with a new email address. You can sign up by clicking this link.
When you've signed up with a new email address, you need to click on your institution name in the top left corner on your home screen and click on 'Link another account'.
On the 'Link another account' page, click on 'Link a Google account'.
Provide your authentication details in the prompt.
Your two accounts are now linked. You now have access to both institutions from your institutions selector in the top left corner on your home screen.