
Hi @Muhamad Fahrurrozi,
For configuring the IRM in SharePoint Server 2019, please see this tutorial: Configuring Information Rights Management. Although this is an old article, it still applies to SharePoint Server 2019.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.