Tutorial
Add to Content Tab many Block Items, select the HTML type and Icons.
Select desired Icon or upload your one, then pass to Item Advanced Tab and change “Use link” to Custom.
Generate with Twig the dynamic link for current Post (or Author, or Terms, etc), here some examples:
FACEBOOK:
https://www.facebook.com/sharer.php?u={{post.link}}
https://www.facebook.com/sharer.php?u={{post.link}}
WHATSAPP:
https://wa.me/?text={{post.link|url_encode}}
https://wa.me/?text={{post.link|url_encode}}
TELEGRAM:
https://t.me/share/url?url={{post.link|url_encode}}&text={{post.title|url_encode}}
https://t.me/share/url?url={{post.link|url_encode}}&text={{post.title|url_encode}}
Other links examples
Twitter: https://twitter.com/intent/tweet?text={{post.title|url_encode}}\x20{{post.link|url_encode}}Pinterest: https://www.pinterest.com/pin/create/button/?url={{post.link|url_encode}}&media={{ post.thumbnail.src|url_encode}}
Facebook: https://www.facebook.com/sharer.php?u={{post.link|url_encode}}
VK: https://vkontakte.ru/share.php?url={{post.link|url_encode}}&title={{post.title|url_encode}}&description={{post.post_excerpt|url_encode}}&image={{ post.thumbnail.src|url_encode}}
Linkedin: https://www.linkedin.com/sharing/share-offsite/?url={{post.link|url_encode}}
Odnoklassniki: https://connect.ok.ru/offer?url={{post.link|url_encode}}&title={{post.title|url_encode}}&imageUrl={{ post.thumbnail.src|url_encode}}\',
Tumblr: https://tumblr.com/share/link?url={{post.link|url_encode}}
Google: https://plus.google.com/share?url={{post.link|url_encode}}
Digg: https://digg.com/submit?url={{post.link|url_encode}}
Reddit: https://reddit.com/submit?url={{post.link|url_encode}}&title={{post.title|url_encode}}
Stumbleupon: https://www.stumbleupon.com/submit?url={{post.link|url_encode}}
Pocket: https://getpocket.com/edit?url={{post.link|url_encode}}
Whatsapp: https://api.whatsapp.com/send?text=*{{post.title|url_encode}}*%0A{{post.post_excerpt|url_encode}}%0A{{post.link|url_encode}}
Xing: https://www.xing.com/app/user?op=share&url={{post.link|url_encode}}
Print: javascript:print(),
Email: mailto:?subject={{post.title|url_encode}}&body={{post.post_excerpt|url_encode}}\n{{post.link|url_encode}}
Telegram: https://telegram.me/share/url?url={{post.link|url_encode}}&text={{post.post_excerpt|url_encode}}
Skype: https://web.skype.com/share?url={{post.link|url_encode}}