How to create a Service Principal Name (SPN) for an AWS RDS-managed SQL Server instance computer object in AD?

We are using AWS RDS for SQL Server, an AWS managed service. We joined our RDS to our self-managed Active Directory:

We found the Active Directory Service Principal Name (SPN) for the RDS-managed-service database instance in the logs, and published that and used it for accessing the database.

However, the SPN changed after a couple of weeks. AWS recreated the instance.

We need an SPN that will not change, so someone thought we should try adding our own SPN and hope that will not change if the RDS instance is re-created. I haven't been able to find any information about static SPNs and RDS. I found Microsoft documentation to use the command:

setspn -S MSSQLSvc/myhost.redmond.microsoft.com:instancename redmondaccountname

However, this requires access to the OS, which I don't have since I'm using a normal RDS for SQL Server (not the custom one). Does anyone have any related experience?

Notes:

• I need a static SPN for PowerBI.

• I'm not using an EC2 instance or RDS for SQL Server Custom (not allowed by my client). I don't have access to Windows Server or any tool inside. I cannot change anything in the OS. Any command must be run from the SQL Server Management Studio or a similar software.