How to get a value in an array based on the sampled value

Questions
7

when i use the DiscreteUniform distribution

    alpha = pm.DiscreteUniform("alpha",  lower=0, upper=5,transform=None)  
    mu = m_test[alpha]*X1

I get the error:

TypeError: list indices must be integers or slices, not FreeRV

When i use the uniform distribution

alpha = pm.Uniform("alpha",  lower=0, upper=5,transform=None)  
 mu = m_test[abs(int(alpha))]*X1

I get the error

int() argument must be a string, a bytes-like object or a number, not 'FreeRV'

So the problem is how I can index m_test based on the variable of FreeRV format.
thanks