According to the docs at https://plugins.jenkins.io/subversion/, a CSRF token (crumb) is needed when submitting to the subversion CI trigger API.

When a crumb is included you get this:

```
Found invalid crumb XXX. If you are calling this URL with a script, please use the API Token instead. More information: https://www.jenkins.io/redirect/
crumb-cannot-be-used-for-script
```

Adding the same token used under the job API doesn't work.