Hello
May I ask are you looking to simply load Font Awesome 5 for your won use within your website content or for specific modules included with your template (J51 Icon, J51 InlineIcons etc)?
To load for your own use you can do the following...
1. Disable Font Awesome in the General -> Typography tab of your template settings.
2. Add the following to the Custom Code -> Head Custom Code field...
<link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.14.0/css/all.css">
<link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.14.0/css/v4-shims.css">
3. Add the following to the Custom CSS field of your template settings..
[class^="fa-"]::before, [class*=" fa-"]::before {
font-family: inherit;
font-weight: inherit;
}
CIaran