Can a Cop in the state of Arizona, make you go to the bathrooom outside while you are in their custody?

An officer cannot technically force anyone to use the bathroom outside
in the person is not willing to do so.  Officers should provide subjects
in their custody a reasonable opportunity to use a bathroom if the need
arises provided it is not going to interfere with their investigation
and it is feasible due to security concerns.  If a person were to use
the bathroom outside, even with the consent or assistance of an officer,
it is a violation of the law.