Support How to change font awesome icons types

[ThanosCrax]

I want to change some FA icons from light [FAL] to duotone [FAD].
Since this is easy for icons using the code:
Like changing fal to fad from the ACP. That's easy ik.

But what can we do for icons like this:

.p-nav .p-nav-menuTrigger i:after {
    font-family: 'font awesome 5 pro';
    font-size: inherit;
    font-style: normal;
    font-weight: 300;
    text-rendering: auto;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    font-size: 24px;
    content: "\f0c9";
    width: 1.28571429em;
    display: inline-block;
    text-align: center;
    vertical-align: bottom;
}