The easiest way to add MyDocSafe client portal to your Squarespace site is by adding a button that leads to the portal login page.
Here you have two options:
use the default login page URL: https://app.mydocsafe.com
use your bespoke login page URL, if you have set it up correctly (for example: https://portals.mybusiness.com). To get the bespoke URL, contact customerservices@mydocsafehq.com