run first time - Error: Path of signatures file is not valid

I downloaded the tar.gz release for Linux. When I run it I get the following error:
```
$ ./ChopChop_linux_amd64 plugins
Error: Path of signatures file is not valid
{"level":"warning","msg":"Path of signatures file is not valid","time":"2022-11-15T10:43:19+02:00"}
```
Where do i get the signatures file as it is not in the tar.gz?
