Yoast not showing keywords

Hi
i am using yoast on my site, my site is near to be completed.my topic is technology News
i am using yoast plugin SEO. last day i open my page View Page Source and i notice after title
<meta name=”keywords” content=””/>
the content is empty ,i write my keywod in yoast Keyword section but still not showing keyword of my any page in coding.
In middle of page i also see Yoast plugin Coding there is also not my keywords.
how can i fix this
plz help me
Thanks