The generator matrix

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

generates a code of length 20 over Z9[X]/(X^2+3,3X) who´s minimum homogenous weight is 36.

Homogenous weight enumerator: w(x)=1x^0+168x^36+324x^38+294x^39+486x^40+648x^41+144x^42+90x^45+30x^48+2x^54

The gray image is a code over GF(3) with n=180, k=7 and d=108.
This code was found by Heurico 1.16 in 0.00798 seconds.