Hi can you help me this reaction kinetics

[BashBedlam]

When I run the posted script just as it is, I get:

Error:
Traceback (most recent call last):
  File "tester.py", line 31, in <module>
    Conc = odeint(rxn,M0,t)
  File "/home/bash/.local/lib/python3.8/site-packages/scipy/integrate/odepack.py", line 241, in odeint
    output = _odepack.odeint(func, y0, t, args, Dfun, col_deriv, ml, mu,
  File "tester.py", line 25, in rxn
    dY1dt = 2*K1*M[1]**3+K2*M[1]*M[3]-K3*M[1](M[3]-M[4])-K4*M[2]*(M[3]-M[4])-(K5+K6)*M[3]*M[4]
TypeError: 'numpy.float64' object is not callable

shell returned 1