node.js - Nodemailer + SendPulse Authorization -

i'm trying use nodemailer sendpulse service i'm getting stuck working through authorization code. i've tried using nodemailer oauth2/3 code samples i'm not sure how access token use future calls... (if understand right).

transporter = nodemailer.createtransport({       service: 'sendpulse',       host: 'smtp-pulse.com',       port: 465,       secure: true,       auth: {           type: 'oauth2',           clientid: 'xxxxx',           clientsecret: 'xxxxx'       }     });      transporter.sendmail({       from: 'xxx@xxx.ca',       to: 'xxx.xxx@xxx.ca',       subject: 'message',       text: 'i hope message gets through!',       auth: {         user: 'xxx@xxx.ca',         refreshtoken: '1/xxxxxsss-xxxxxxxxxxxx0xxxxxxxx0x00xxx',         accesstoken: 'ya29.xx_xx0xxxxx-xx0x0xxxxxxxxxxxx0x',         expires: 1484314697598       }     }); 

how refreshtoken/accesstoken required above?