Getting error message when adding custom property. What am I doing wrong?

Hi there, I’m trying to add a button to my email so when the user clicks on it they are automatically added to a segment. I must be doing something wrong but can’t figure it out. The code I’m using is:

{% update_property_link ‘newdesign_earlyaccess' 'true' 'https://mysite.com' %} 

I added the property to my own profile to create it. But I must be missing something. 

Can you help? I’m hoping to get this out in the next couple of hours but hitting a brick wall!