Is your feature request related to a problem? Please describe.
This application currently only supports Secrets Manager for remote secret storage. Secrets Manager is $0.40/secret/month.

Systems Manager Parameters are equally secure (can be KMS encrypted) and are free. Since none of the other Secrets Manager features are necessary for this application (rotation, replication), use of Secrets Manager is not strictly required.

Therefore, Systems Manager Parameters would be a preferred secret store for some users.

Describe the solution you'd like
Allow specifying Systems Manager parameter names/ARNs instead of only allowing hard-coded Secret names.

Describe alternatives you've considered
Keep using secrets.