How do I even get to the MPU, how is it ordered, do I have to make an application?

The man looked only briefly in his comp. and said I had to do an MPU, then he told me what I could do better, e.g.: an MPU consultation, then that paid would be better, because there are also free ones. There I am told whether I need an abstinence test or not. And then after this consultation or seminar I should go to the MPU, where a psychologist tests me. And that I have the application at the Z I should take flyers with me. But I don’t get smart from the flyers. What’s the right thing? There were addresses of psychologists (free advice), then flyers with the inscription of special construction seminar according to §§ 2 b, 4 StVG and §§ 36, 43 FeV or course for the restoration of the motor vehicle fitness according to § 70 FeV for alcohol-responsive drivers. The latter is however arranged according to an MPU. ??? The man h but should not such an MPU be ordered in writing and if so I have to go there or can choose an appointment. Somehow I don’t know what to do at all. Which steps to take and where to go.