How to get value from all elements of an array?

Question

PHP

I apologize in advance for the question, I don't know how to google it.

There is a line:

print_r($insta_array['entry_data']['ProfilePage'][0]['graphql']['user']['edge_owner_to_timeline_media']['edges'][1]['node']['thumbnail_src']);

It displays the URL of a specific post that I need.
I need to get all such urls of all posts.

But, I don't know how to write instead [1]['node']['thumbnail_src']
to get the URL of all posts.
Like so?
[ (all?) ]['node']['thumbnail_src']
That is, instead of a number at the end, I need to insert the value of all elements of the array. How to do it? Thank you.