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