The realization space is
  [1   1   0   0            x1*x2 - x2     x1*x2 - x2   0   x1   x1            x1*x2 - x2    1]
  [0   1   1   1   x1^2 - 2*x1*x2 + x2   x1^2 - x1*x2   0    0   x1   x1^2 - 2*x1*x2 + x2   x1]
  [0   1   1   0                     0     x1*x2 - x2   1   x2   x2        x1*x2^2 - x2^2   x2]
in the multivariate polynomial ring in 2 variables over ZZ
avoiding the zero loci of the polynomials
RingElem[x1^2*x2 - x1^2 + x1*x2 - x2, x2, x2 - 1, x1 - 1, x1 - x2, x1^2 - 2*x1*x2 + x2, x1, x1^2 - x1*x2 + x2, 2*x1^2*x2 - x1^2 - 3*x1*x2^2 + x1*x2 + 2*x2^2 - x2, x1^2 - 3*x1*x2 + 2*x2, x1^3 - x1^2*x2^2 - 3*x1^2*x2 + 2*x1*x2^2 + 2*x1*x2 - x2^2, x1^3*x2 - x1^3 - 2*x1^2*x2^2 + 3*x1^2*x2 - 2*x1*x2 + x2^2, x1^3 - x1^2*x2^2 - 3*x1^2*x2 + 4*x1*x2^2 + x1*x2 - 2*x2^2, x1^3 - x1^2*x2^2 - 2*x1^2*x2 + 2*x1*x2^2 + x1*x2 - x2^2, x1^2*x2 - x1^2 - x1*x2^2 + 2*x1*x2 - x2, x1^2 - x1*x2^2 - 2*x1*x2 + x2^2 + x2, x1^3 - 3*x1^2*x2 + x1*x2^2 + 2*x1*x2 - x2^2, x1^3 - 3*x1^2*x2 + 3*x1*x2^2 + x1*x2 - 2*x2^2]