First you add a new post. Then you go to “Add Media” and choose an image.
Then you click the button “Insert into post”. Now you can see it in the visual editor of your post.
Don’t forget to save. Click “Save Draft”.
Now hover with your mouse and select the image in the editor until it highlights.
Press “Insert/edit link”.
Put any link you want in the pop-up small box: affiliate link or any URL.
Now publish the post and visitors can click the image 🙂