Hi Elvin,
I tried adding the target="_blank" attribute at different points in the code above, but the code-editor wouldn’t accept it (basically deletes the whole line of code, when I try to update the page).
Could you show where exactly to place it in this line of code: <!-- wp:social-link {"url":"https://facebook.com/","service":"facebook"} /-->
Its Buttons block allows you to add Icons and remove the link text and style them however you want. When you add the link URL click the 3 dot menu where you can select a new tab.