When you are on the window to write.
You have on top of it, a bar with some button, one is called "host an image"
It goes to servimp.com, I register on it first.
https://servimg.com/So I could have access to the pictures, I put on it.
Then when you want to host, you clic on the icon.
It's asking you to upload an image from your computer.
So you clic on "choose" then you navigate to the file and you select it.
Then you will see the name of your file on it.
Now you have to send the picture with the button below.
The system is recalibrating the picture for the forum.
It's uploading, take time depending on the size of the picture.
If you want to embeded the picture, you have to copy the full link sentence, onto the window where you are writing
So you choose the link from "image"
And you paste it on the window where you are writing.
Try some test and look at preview first to get use to it.
Should work now.