Medical report for IQAMA visa

I am looking for someone who applied from Germany for a Residence VISA for his family. I struggled to get the medical report correctly authorised. I have printed the form and the Hausartzt (family doctor) filled it correctly after doing all the blood tests and x rays. Now how to get this report authorised and get Apostille on it.

Do I really need to have an appointment of the Gesundheitamt (German Minstery of health) or any other place before sending it to the Apostille.

I am unsure how to proceed because I am unable to reach someone from the Saudi embassy and online I find even more confusing information. In order to clarify how to get this medical report accepted.

So, if there is by any chance any German here that has applied for a Work VISA or IQAMA and can let me know how to handle the medical report.

If someone perhaps knows a subreddit or where to ask/look this would be great too.