Error running r script in ADF pipeline using Azure Batch: can't find file

Hello, I'm struggling to run a data factory pipeline that executes an R script which is stored in a blob container. When trying to run the pipeline, I receive this error:

{"errorCategory":0,"code":"CommandProgramNotFound","message":"The specified command program is not found","details":[{"Name":"Message","Value":"The system cannot find the file specified"}]}

Here is the single Custom activity:

The Batch and storage linked service connection tests were successful. The R script (UpdatedPoss_ForAzure.R) is stored in the r-script-test folder:

Here's the pool in Batch account: