My proposed change may not be right, but "make a request to URL" was unclear, and it's `fetch` that's used below to make the request. If 'request to URL' has some special meaning and is what you want to say, maybe some rephrasing is in order.

Confucius never said anything about black cat

Ref: https://www.washingtonpost.com/world/2019/03/25/chinese-proverb-that-russia-cited-respond-mueller-report-does-not-appear-be-chinese-proverb/

"// obj.toString === obj.__proto__.toString == Object.prototype.toString"
It is look like JS code but it gives different result from what we want to get.
There is different kind of equality operator ant these give more confusing what is the purpose of these?
It can be better to separate this line into 2 line of code to make it sensible and readable.
Subject and code is already hard but there is no need to make readers ask unnecessary questions.

An interesting question may arise in the example above: what’s the value of this inside set fullName(value)? Where are the properties this.name and this.surname written: into user or admin?

The answer is simple: this is not affected by prototypes at all.

No matter where the method is found: in an object or its prototype. In a method call, this is always the object before the dot.

So, the setter call admin.fullName= uses admin as this, not user.

That is actually a super-important thing, because we may have a big object with many methods, and have objects that inherit from it. And when the inheriting objects run the inherited methods, they will modify only their own states, not the state of the big object.

The example code doesn't show these concepts. Also, these additions can make readers ask questions before the explanation of the example code.

Small fixes.

Added link to Brython Python transpiler to JavaScript

add semicolon 13,20 line

Explained how to create a date object.

Knowledge correcting: Delete "Trident"

Dynamic script document order execution is done with async=false

Fix old link and excess line break in 1.2.8

Fix grammar and construction in 2.1.10

PR for issues/2119

Add Edge to list of V8-powered browsers

Changed "position" to "index" for slice() method

Address some possible inconsistencies in 1.2.9

Fix typo in 1.2.12