Bayesian probability for an final event based on two prior sequential events

Question

say i have a a three step process for a business outcome.

user login and register the course, say the probability of registration is P(R) user complete 50% of the course, say the probability of is achievement is P(A) user complete the 100% of the course,, say the probability of completion is P(C)

Now, if i assume these processes are independent then the probability a user will complete the course ( by registering for the course, complete it 50%, and then complete is 100%) is:

P(A)*P(A)*P(C)

However, these events are not independent, as P(A) depends on P(R) and P(C) depends on P(A) and P(R).

So, if I have to do it via bayesian how would I calculate this.

Sorry, I am new to this and maybe completely missing something.

thanks for the help