I change the size and shape of mine in the theme editor.
not sure if this is how its done but worked for me.
.fa-bell {
--far: "\f0f3";
--icon: '\f0f3';
color: white;
opacity: .5;
min-width: 1.2em;
text-align: center;
font-weight: 900;
font-size: 20px;
}
.fa-classic, , .far-solid, .fas {
font-family: "Font Awesome 6 Free";
}
.fa-envelope {
--fa: "\f0e0";
--fa--fa: "\f0e0\f0e0";
color: white;
opacity: .5;
min-width: 1.2em;
text-align: center;
font-weight: 900;
font-size: 20px;
}
.fa-flag{
--fa: "\f071";
--fa--fa: "\f071\f071";
color: white;
opacity: .5;
min-width: 1.2em;
text-align: center;
font-weight: 900;
font-size: 20px;
}
.fa-file-alt, .fa-file-lines, .fa-file-text {
--fa: "\f15c";
--fa--fa: "\f15c\f15c";
color: white;
opacity: .5;
min-width: 1.2em;
text-align: center;
font-weight: 900;
font-size: 20px;
}