Make a 3×5 grid

Reorder columns has 3, 1, 2

dar68human987kj

Make a 6×6 grid

From this we can see that O was used to pad the string. Read going up from the lower left 9 and make pairs

98 7e 7b ae ad 8e 7d 86 78 aa ad ad 7f 97

Look at where number positions should be, they all start with A. Hex atbash using this index

0123456789abcdef
fedcba9876543210

67 81 84 51 52 71 82 79 87 55 52 52 80 68

Convert decimal to Ascii

CQT34GROW744PD