How to add images to README.md on GitHub?

Try this markdown:

![alt text](http://url/to/img.png)

I think you can link directly to the raw version of an image if it's stored in your repository. i.e.

![alt text](https://github.com/[username]/[reponame]/blob/[branch]/image.jpg?raw=true)

You can also use relative paths like

![Alt text](relative/path/to/img.jpg?raw=true "Title")

Also try the following with the desired .fileExtention:

![plot](./directory_1/directory_2/.../directory_n/plot.png)

• You can create a New Issue
• upload(drag & drop) images to it
• Copy the images URL and paste it into your README.md file.

here is a detailed youTube video explained this in detail:

https://www.youtube.com/watch?v=nvPOUdz5PL4