Facebook Login With WP JWT Auth
Yesterday I opened a bounty for your question and today I'm answering it!
You will need two WordPress plugins: stionic users and nextend social login (you need to configure it on order for stionic to work. Watch the video on that page in order to know how to configure it)
When done you could send a post request to https://example.com/wp-json/wp/v2/m_facebook/loginin postman and you will notice that you will get the same token that you get when logging in https://example.com/wp-json/jwt-auth/v1/token
After that, you can configure facebook ionic plugin and you are done.
JSON API User plugin is an alternative but I haven't tried it
Useful tutorials