import numpy as np
from gekko import GEKKO
m = GEKKO(remote=False)
m.time = np.linspace(0,5)
x = m.Var(0)
m.Equation(x.dt()+x==12)
m.options.IMODE=4
m.solve(disp=False)

import matplotlib.pyplot as plt
plt.plot(m.time,x)
plt.show()