Instagram Basic Display - How do I get USER ID?

I have the Instagram basic Display api set up and working ok to get my data. However if I try to get a user data (not mine), non of the ids work.

Here is how am searching in python code but its failing:

media = instagram_basic_display.get_user_media(user_id='nnnnn')

If I insert the user is from the url, it doesn't work.

What is the correct user_id to use in the above code in place of 'nnnnn'?

from Instagram Basic Display - How do I get USER ID?