<< KnotTheory`

L=PD[
X[1,20,2,9], X[2,7,3,6], X[5,4,6,3], X[8,17,5,16], X[9,4,10,1],
X[11,18,12,19], X[13,11,14,10], X[15,8,16,7], X[17,12,18,13], X[19,15,20,14]
];

ArcPresentation[L] // Draw

MultivariableAlexander[L][t] /. {t[1]->u, t[2]->v, t[3]->w}