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E and W are not isomorphic over K, so to map the point you need to first extend scalars to a field where the curves become isomorphic.
In this case that field is K[x]/(x³ - 2), so you may do:
sage: R.<x> = K[]
sage: Kext.<z> = K.extension(x**3 - D)
sage: iso = E.change_ring(Kext).isomorphism_to(W.change_ring(Kext))
sage: iso(G)
(40216402057367404040950003906398818325277679584028406643169464361823622385192*x : 43475077929003398730357028969543559394773055995479050704508650707585105896924 : 1)
Note that in principle you could try to construct Kext as K.extension(3), but that takes forever because Sage spends an insane amount of time looking for a special irreducible polynomial, so better provide the polynomial yourself.
