here are two more way to create clickable link in your post.

1. You need microsoft word or other text processor. Copy target link into workspace and push ENTER. Link will turn into 'live' automatically. Then copy this link in italki.

2. (more complex way) Create an HTML document. Then put following code into this one:

<a href=YOUR_URL>Link title</a>

Then open is with browser and copy that link into italki. Here an example: <a href="https://italki.com/" style="font-family: 'Times New Roman'; font-size: medium; line-height: normal; background-color: rgb(255, 255, 255);">Visit ITALKI right now</a>

That's interesting. I'll have to try it. I think Miguel is saying that even though "being a link" is not available on the toolbar, it is nevertheless an attribute that can be copied, pasted, and accepted by the italki editing box in the "discussions" section. 

I have to try this.

<a href="https://www.dropbox.com/s/d0d5a48vrexzvr8/Factory%20windows.mp3?dl=0" style="color: rgb(17, 85, 204); font-family: Arial, Helvetica, sans-serif;">Factory Windows are Always Broken</a>

It seems to work.

Here's a possible issue: I'm guessing that italki probably doesn't want people to do this, or they would have made a "link" button available in the editing toolbar.

Turnabout is fair play, Miguel, so here's a tip for you. You may have noticed that the italki editor won't accept an ampersand character. A workaround I sometimes use is to paste in a Unicode character called "fullwidth ampersand" which isn't an ampersand and isn't going to create whatever risk they are trying to defend against, but looks like an ampersand. Here it is:

Fullwidth ampersand for italki: ＆

Thanks for the great info Miguel, I haven't been able to figure out how to do it in a more efficient way.