XF 1.5 Tooltip url pop up thing how to code?

I want to code a url for my custom userfields but I want it when you hover it, it pops up a tooltip like this saying Click here to go to my game profile

Example pic: Screenshot_3.png

the black thing you see when you hover your mouse

heres the code i want to put it in

<a href="https://gameprofile.com/{$valueUrl}" target="_blank" >{$value}</a>