Installing and Configuring Social Login Extension in Magento 2

Download and Install MagePlaza Extension.
SSH to your server add following command in CLI to finish installation.

rm -rf var/di/* var/generation/* var/cache/* var/log/* var/page_cache/* var/session/* var/view_preprocessed/* pub/static/*
php bin/magento cache:clean
php bin/magento cache:flush
php bin/magento setup:upgrade
php bin/magento setup:db-schema:upgrade
php bin/magento setup:di:compile
php bin/magento setup:static-content:deploy
php bin/magento indexer:reindex

To configure it, go to MAGEPLAZA > Configuration > Social Login and expand the general section. Enable the extension from there.
Source: https://www.cloudways.com/blog/add-social-login-in-magento-2/