To add Google Search Console to Squarespace, you can follow these.
#1. Access Google Search Console and click Start Now
#2. Enter the domain name and click Continue
#3. Wait a moment
#4. Google will ask to verify the domain name. You can choose the most suitable way. Here I am using a domain name from Godaddy, so I will choose to verify with Godaddy.
#5. It will open a page (or a popup), you need to log in to Godaddy
#6. Click Connect
#7. and wait
#8. Done
#9. Now you can access Google Search Console. It will take about 24 hours for Google to display data from the website.