# What this PR does
Allows passing `null` as a value for `escalation_chain` when creating
routes via the public API.
## Which issue(s) this PR fixes
This is needed to unblock https://github.com/grafana/oncall/pull/1555 +
creating a route without an escalation chain is possible in the web UI,
so this PR makes the public API more consistent with the web UI.
## Checklist
- [x] Tests updated
- [x] Documentation added
- [x] `CHANGELOG.md` updated