The generator matrix

 1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  X  X  1
 0  X  0  0 2X X+3 2X+3  X 2X  6  3 X+6 2X  6  6  6 2X X+6  6 2X+3 X+3
 0  0  X 2X  6 2X+3 X+6  X 2X+3  3 X+3 X+3  3  0 2X+3 2X+6  3 2X+6 2X+3 X+3  3
 0  0  0  6  0  0  3  6  3  3  3  3  6  6  3  0  3  3  6  3  6

generates a code of length 21 over Z9[X]/(X^2+3,3X) who´s minimum homogenous weight is 36.

Homogenous weight enumerator: w(x)=1x^0+144x^36+96x^37+180x^38+326x^39+798x^40+372x^41+2230x^42+1404x^43+342x^44+302x^45+84x^46+72x^47+146x^48+48x^49+6x^50+8x^51+2x^57

The gray image is a code over GF(3) with n=189, k=8 and d=108.
This code was found by Heurico 1.16 in 0.0605 seconds.