You should be able to check the Dockerfile for what it is doing during the build (it's a glorified shell script).
## User-Agent Configuration
## Configuration
`config.template.yml` has an example.
You can set the `User-Agent` globally in your `config.yml` file:
First, set the `User-Agent` globally in your `config.yml` file. Note that it isn't currently used for all scrapers as some require mimicking a browser.