If the verdict is passed, immediate family members should bring their ID cards to the detention center to apply for an interview. After applying, the detention center will give you a reply within 10 days. If the detention center notifies you that your application was successful within 10 days, you can go to the interview with your ID card and interview certificate.
If there is no verdict. With your ID card, you can send things or money, but you cannot meet with them. You can only entrust a lawyer to meet with them.
The detention center phone number: 010-82587322: 010-82587322. If you are not sure, you can also call for consultation.
I hope my answer can help you. If you are still unclear, you can find me through the link below.
Your friend, Lawyer Zhao Li of China Criminal Defense Network