Use a computer or change your phone broswer to a computer version. It does not work on mobile version
Visit https://imgur.com
At the left upper corner, click on 'new post'
Then click on 'choose image'
Choose the image you want to post
It will be uploaded on the site
On the image, click on the leftmost upper corner
Click on the three dots that appear
Click on 'get shared links'
Then click on BBCode (Forums)
Paste the image here on this forum.

It will look like this:


If the image has later appeared, to resize, adjust the height and width.