_total no longer avaible

No

iterate all pages and add it up yourself

Using you example where you are calling a predefined set of channels.

Count the size of the helix {data:[]} in the response

link = 'https://api.twitch.tv/kraken/streams/?channel=' + channels

Would become

link = 'https://api.twitch.tv/helix/stream?user_id=x&user_id=x&user_id=x&user_id=x'

(You may also need to include the first if calling more than 25 ID’s)

And then count the size of the data key in the JSON response