Here 2 ways to add Share Icons into Blog Posts Squarespace
Option 1. Add Social Share Icons with Shareaholic
First, access Shareaholic.com and click Get stared for free today
Next, create a free account
Add a website
Enter your Squarespace site (I haven’t connected with live domain yet so I use built-in domain)
Choose Squarespace
Copy the embed code
Add to Settings > Advanced > Code Injection > Header (or Blog Page Header)
Next, click Start App Setup
Click Social
Click Settings
Then you can adjust everything!
Result
Option 2. Add Share Icons use Elfsight
First, access this share widget site & click Try a demo
Select a template (You can adjust share icons then)
Design your Share Icons, then click Add to website
Example
You will need to create a free account, then click Apply > Save
Choose Lite (Free) Plan
Copy the embed code
Add it to Settings > Advanced > Code Injection > Header or Post Blog Item Code Injection
Result