STEP 1: In Studio, go to Settings > Member Area > Website Integration > Login Form Integration:
On this page you'll see a number of steps, ignore these for now, but you'll need some of this information later.
STEP 2: In a new tab/browser, login to your SquareSpace editor. In the left menu, select 'Settings':
Then 'Advanced':
Then 'Code Injection':
In this HTML box, copy/paste in the code under Step 1 in the Studio Login Form Integration:
Save the changes.
STEP 3: Next, go to your 'Pages', and select the page you wish to add the sign-in form to.
In the editor, hover the mouse over the area and click the icon as demonstrated below:
Now browse down and select 'Code':
Copy/paste in the following code from 'Step 2' from the Studio Website Integration page, then apply:
<div id="studio-member-login"></div>
NOTE: You may not see the login form straight away, sometimes you need to refresh the page or preview/publish your website to see it:
You're all done!