Install social plugin that has it's own SHORTCODE and add it to Theme Options - Socials - 'Login via Social network' field. We recommend: Wordpress Social Login
James 1:21 New King James Version (NKJV) Doers—Not Hearers Only 21 Therefore lay aside all filthiness and [a]overflow of wickedness, and receive with meekness the implanted word, which is able to save your souls.