Issue with fetch on Wikipedia problem

On the wikipedia problem I’ve hit a snag, Using fetch, the response I’m given I cannot use. At least I don’t know how.
This is only to show my issue, hence all the loops.I only did these loops to see if they allowed me something I could not get by clicking in the console.

const endpoint = '*&titles=Albert%20Einstein'
    .then(blob => blob.json())
    .then((data) => {
    for(var i in data){
     //returns batch complete ,
      //& query
      for(var j in data.query){ 
         //returns pages
        for(var k in data.query.pages){
        //returns the string 736

I cannot go any further than this 736. Along with the gibberish above when I open the object all I see are the object methods. How do I dig into the return data? Where the heck is it?
What am I doing wrong?