As is explained in the post, to run ALM you need a server (Lagotto) and a client (your OJS plugin).
AFAIK, ALM server is overwhelmed and not accepting more institutions so right now is not possible to run “Alternative metrics” unless you build your own ALM server installation.
This “common” server was paid and maintained by PKP but it means a hight cost and we are now under-discussion about new models to keep it running.
This video could help to get context: http://pkp.sfu.ca/pkp2015/public/video/pkp2015-agm-6.html
Note: Without a ALM server is possible to setup your ALM plugin to show local statistics (ie: http://atheneadigital.net/article/view/v15-n2-roman), but never from social networks, that need to be collected by Lagotto.