Is there a way to setup Algorithm Keyset for symmetric encryption that uses secret key keystore?

We can get symmetric AES to work using a 'key' that is typed in directly.

The issue is that our cyber-security folks are telling us it is not acceptable to do this. The encryption key needs to be 'secure'.

I understand that AES symmetric algorithms use a 'secret key'.

Is there any way to have PS create a keystore that would hold the 'secret key' needed for AES symmetric algorithms?