During criminal detention, you can make phone calls with approval, but you can't make phone calls without approval. Article 28 of the Regulations on Detention Centers stipulates that criminals may communicate and meet with their close relatives with the consent of the case-handling organ and the approval of the public security organ during their detention.
Legal objectivity:
Article 39 of the Criminal Procedure Law: A defense lawyer may meet and correspond with a criminal suspect or defendant in custody. Other defenders, with the permission of the people's courts and people's procuratorates, may also meet and correspond with criminal suspects and defendants in custody. If a defense lawyer holds a lawyer's practice certificate, a law firm's certificate, a power of attorney or a letter of legal aid to ask for a meeting with the criminal suspect or defendant in custody, the detention center shall arrange the meeting in time, which shall not exceed 48 hours at the latest.