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

generates a code of length 20 over Z9[X]/(X^2+6,3X) 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 0.00793 seconds.