Check custom audience email list - facebook

Question

I am using facebook/php-ads-sdk: 2.5.*
I created new custom audience using SDK.
Then manually added user by emails.
Then I check my custom audience list
And checked Audience History
which seems fine to me
My recent audience history
but
That shows me Audience is not available
which suggest me that
Audiences must include at least 20 people to be used for ads.
So I added 20 user manually
Still Facebook showing me this list is not available for same reason.
How can I check the list of user?
What did I miss?
When I use graph api explorer it shows me
(#10) You do not have sufficient permissions to perform this action
And by using php sdk I can read only approximate count which is 20 already.

Answer 1

It's likely that the audience does not have more than 20 people in it, as not 100% of your email addresses matched users. Unfortunately you cannot know which ones did and did not match.
You can check the approximate count in the audience by doing:
$audience = new CustomAudience($id);
$audience->read(array(CustomAudienceFields::APPROXIMATE_COUNT));
echo $audience->{CustomAudienceFields::APPROXIMATE_COUNT};