Snyk offers fix advice, which can include recommendations for upgrading vulnerable packages with our automated Fix PR feature. Automated Fix PRs can only be created for dependencies whose versions are managed as part of the repository itself.
If you receive the error Failed to open a Fix PR, then most likely you have asked Snyk to create a Fix PR to upgrade a dependency, but the version of that dependency is managed externally to the repository that you've integrated with.
If the dependency must be managed external to your project, we recommend you ignore the issue.