What is the best way to add a social media share button?

Hi there,

you need a plugin.
Some of my personal choices:

Premium: https://novashare.io/

Free: https://wordpress.org/plugins/shared-counts/

Hi,
i've found this post to create share icon without plugin.

https://webinsights.in/social-share-buttons-without-plugin-in-generatepress-theme/

Do you think that is a good solution?

It's tough for us to tell but I would say that the plugin solution David suggested is probably more reliable.