See [official documentation](https://github.com/vanderbilt/redcap-external-modules/blob/testing/docs/official-documentation.md#available-developer-methods-in-external-modules) and [issue](https://github.com/vanderbilt/redcap-external-modules/issues/246#issuecomment-579413815). Recommend something like `sed s/ExternalModules::/$this->/g` to correct but each line will need to be inspected.