On Qiskit qiskit==0.44.1:
qc.qasm()
E.g. with our qiskit/hello.py, we obtain the Bell state circuit:
OPENQASM 2.0;
include "qelib1.inc";
qreg q[2];
creg c[2];
h q[0];
cx q[0],q[1];
measure q[0] -> c[0];
measure q[1] -> c[1];