Click the "Insert Hyperlink" button on your message editor. "url][/url" will pop up.(I had to remove the brackets at the ends, or the hypertext would disappear.)
After the first "url", add the = sign, then add the url of the website you are trying to link, like this: url=https://pelletfan.com/index.php][/url
Next, add the title of the link in between the urls, like this: url=https://pelletfan.com/index.php]Pelletfan[/url
You should get this:
PelletfanGood luck!