You can find the exams guidelines here: Prüfungsordnung des Goethe-Instituts
Here are the terms and conditions for exam administration B1: Durchführungsbestimmungen Goethe-Zertifikat B1
Find our detailed terms and conditions at 考生必读!歌德语言证书考试须知 | 备考建议、证书邮寄、成绩复查等事宜