For cookie popup:

 

1. Open https://squarespace.com

2. Select your website

3. Go over to "Settings"

4. Scroll down and click "Advanced"

5. Click "Code Injection"

6. Then you should be able to paste your code snippet

 

For policies:

 

1. Go to the "Editor"

2. Click the "+" Icon

3. Then click "Embed" icon

4. Then you should be able to paste your code snippet