aspnet_regiis.exe/alternative for .net core 3.1 encryption

Question

I have a .net core 3.1 web api and am using IIS to host the application. I'm trying to encrypt the environment variables section of the published web.config using aspnet_regiis.exe but the command throws the section not found error. I couldn't find any official docs that says if this is even possible. We do use a secure management tool to store the application secrets but we need to have certain secrets on the hosted server. Is there anything that is available out of the box in IIS that can do this instead of having to create the custom encryptor/decryptor ?