I applied for a summary card and will I need an approval for my card to show in my tweets because it has been weeks now. Also, I read that it doesn't need approval but I don't see a card whenever I link my blog to my tweet.
Another question, will I need to validate my card again if I change a code in my blog? Thanks
Can you provide an example URL where you have implemented summary cards markup, and a link to a Tweet that does not show the summary card?
You definitely do not need to apply or be approved for summary cards, and the validator usually covers the whole domain.
I put the markup on my blog: http://ofcoffeeandbooks.blogspot.com and here's a tweet where the card doesn't show up: https://twitter.com/sageherondale/status/732844535533998081
You have markup on the top-level page on your site, but not on the individual posts like the one you link to in that Tweet.
Also, the value for twitter:image is incorrect in the top-level page.
what is the markup for individual posts?
here's the markup for my twitter image
<meta content='Image URL' name='twitter:image:src'/>
do I have to remove the :src? or do I have to replace the IMAGE URL and post a specific link to an image?
Both. src is no longer used, and you should point to a valid image URL.
As for individual posts, you should choose your own appropriate images and descriptions etc.