https://imgur.com/a/aKwPFGw On mobile so I think it’ll just be a link Edit: Picture from computer this time.
Copy it. In Safari on iOS this is a built-in option when holding an image, I'm not sure about other devices. In any case, you could always open the image in a new tab (also by holding it and then selecting that option), copy the link, and write the [img] tag manually. But it probably isn't necessary, as I would expect Android's internet browser to have an option for copying the image right away too.
I use chrome on my mobile which does sadly not have any editor. I copy the link and paste it in between the tag as 607 states Code: [img]imageurl[/img]