@KHALED ZEINAB Thanks for your patience on this.
I have checked with Azure Communication Engineering team and sharing the below.
As mentioned in the documentation here, currently messaging, voice and video calling are supported in US Gov regions for Azure communication service.
Email Service in ACS for US Gov regions is in our product roadmap and might be available from FY25. Also note that this is not the exact ETA and may be subject to change based on various factors.
Hope this helps let me know if you have any further questions on this.