For the email encryption report, you can use the Get-MailDetailEncryptionReport cmdlet:
e.g. Get-MailDetailEncryptionReport -StartDate 05/01/2024 -EndDate 05/12/2024
To get all the DLP alerts across workloads, you can use the Graph API's /alerts_v2 endpoint instead and filter DLP as the source:
https://learn.microsoft.com/en-us/graph/api/security-list-alerts_v2?view=graph-rest-1.0&tabs=http