GAP 4.8.9 installation with standard packages -- copy to your CoCalc project to get it
1
2gp
2 #prime
6 #maximum class
1 #print level
{a, b} #generating set
{ [b, a, a], (a * b * a)^4 } #defining set of relations
0 #exponent
2 #save option
2GP #file name
0 #exit