How to change "link icon" after the post?

I want to replace the link icon with the share icon since that is what my community is more familiar with. I tried the css methods available here on meta but they aren’t working anymore. I also saw a post about changing icons globally. But, I don’t want to change that icon globally, that way the icon will also change in the editor.
What’s the way to change the link icon just after the post and nowhere else. Thought, adding an image might help. Need to change the icon here in the image.
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