Location search is returning error

I am trying to implement a location search as described in here – https://wpmaps.mapster.me/examples/mapster-wp-map/custom-search-geocoder/

I have added the mapbox token in the settings, however, I am seeing below error when I try to search location

"message": "Stack \"5\" is not a known stack. Must be one of: aa, ad, ae, af, ag, ai, al, am, ao, aq, ar, as, at, au, aw, ax, az, ba, bb, bd, be, bf, bg, bh, bi, bj, bl, bm, bn, bo, bq, br, bs, bt, bv, bw, by, bz, ca, cc, cd, cf, cg, ch, ci, ck, cl, cm, cn, co, cr, cu, cv, cw, cx, cy, cz, de, dj, dk, dm, do, dz, ec, ee, eg, eh, er, es, et, fi, fj, fk, fm, fo, fr, ga, gb, gd, ge, gf, gg, gh, gi, gl, gm, gn, gp, gq, gr, gs, gt, gu, gw, gy, hk, hm, hn, hr, ht, hu, id, ie, il, im, in, io, iq, ir, is, it, je, jm, jo, jp, ke, kg, kh, ki, km, kn, kp, kr, kw, ky, kz, la, lb, lc, li, lk, lr, ls, lt, lu, lv, ly, ma, mc, md, me, mf, mg, mh, mk, ml, mm, mn, mo, mp, mq, mr, ms, mt, mu, mv, mw, mx, my, mz, na, nc, ne, nf, ng, ni, nl, no, np, nr, nu, nz, om, pa, pe, pf, pg, ph, pk, pl, pm, pn, pr, ps, pt, pw, py, qa, re, ro, rs, ru, rw, sa, sb, sc, sd, se, sg, sh, si, sj, sk, sl, sm, sn, so, sr, ss, st, sv, sx, sy, sz, tc, td, tf, tg, th, tj, tk, tl, tm, tn, to, tr, tt, tv, tw, tz, ua, ug, um, us, uy, uz, va, vc, ve, vg, vi, vn, vu, wf, ws, xk, xs, xx, ye, yt, yy, za, zm, zw, zz, xb, xc, qq, dg"

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