Number of passenger or crowding API

Hi, I’m looking for numeric data of how underground is crowded. I’m an art student and working on a project to visualize the crowdedness with a different sense.

Thus, Ideally live-time but at least very up-to-date data.
It seems like the Crowding API on TfL is not a numeric dataset, isn’t it?
Also, I found some sample data from 2018 and some bit of recent data here -
http://tap.data.tfl.gov.uk/
Our open data - Transport for London
And there’s a notion on the number of passengers section that “you need to [register to gain access to the live feeds] which led me to the api website).” - Is there any equivalent data set that I couldn’t find yet??

If there’s no numeric data that I can use on TfL… Can anyone recommend me another way to achieve some similar data?

Thank you so much