If your application for asylum was ultimately denied, you are under the obligation to depart the country and therefore have to leave Germany. If due to particular reasons, such as a grave illness, you are not able to leave the country, the Aliens Authority can issue a temporary suspension of forced return. This temporary suspension of forced return confirms that you cannot be returned for a particular period of time. During this time you remain under the obligation to leave the country but will not be taken back to your country of origin by force.
If a temporary suspension of forced return is not issued to you, the Aliens Authority may carry out the forced return (deportation) if you do not leave the country within the deadline given to you.
Further information regarding voluntary return can be found under the point “voluntary return“.