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javascript - access blob value outside of canvas.ToBlob() async function

I'm working with HTMLCanvas element that return the blob object outside of the async toBlob() function. This function doesn't return an output value, so I'm trying to declare a variable outside and access it through the command.

How I can use JS Promise for this scenario?

var myblob;
            canvas.toBlob(function(blob) {                         
                              myblob = blob;
                              console.log("inside " + myblob); // getting value after the console outside
                           })
 console.log( "outside " + myblob); // getting undefined   
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const blob = await new Promise(resolve => canvasElem.toBlob(resolve));

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