[Website]: Add missing prerequisites to AWS Billing integration docs

**Page:** https://www.elastic.co/docs/reference/integrations/aws/billing

The [What do I need to use this integration?](https://www.elastic.co/docs/reference/integrations/aws/billing#what-do-i-need-to-use-this-integration) section is missing two prerequisites that are easy to overlook:

- AWS billing metrics are stored in the `US East (N. Virginia)` (`us-east-1`) region only. The integration's region must include `us-east-1` to collect data.
- Billing alerts must be enabled in AWS. See [Enabling billing alerts]((docs.aws.amazon.com/redacted) in the AWS CloudWatch documentation.

**Definition of done:** Both prerequisites are added to the "What do I need to use this integration?" section of the AWS Billing integration page.

---
🤖 _Refined by RefineBot on 2026-06-26. Original intent preserved._

RefineBot changes

**What changed:**
- Fixed title grammar ("requirement" → "requirements") and added integration name for specificity
- Removed empty list item between the two requirements
- Added explicit definition of done
- Restructured body with page link at top for scanability

**What was preserved:**
- Both requirement bullet points and their content
- Author's link to AWS CloudWatch documentation
- Specific section URL target

Previous version

### Before you submit

- [x] This issue is about a documentation page, flow, or piece of content.

### Type of issue

Missing information

### What documentation page or section is affected

https://www.elastic.co/docs/reference/integrations/aws/billing

### What happened?

This integration needs two more very important requirement to collect data that any user can easily miss:

- As the metrics are stored in the `US East (N. Virginia)` region only, the integration's region should include `us-east-1` region
-
- To collect the billing metrics, the user should enable the billing alerts by following this AWS reference: (docs.aws.amazon.com/redacted)

Add these two bullet points into the section https://www.elastic.co/docs/reference/integrations/aws/billing#what-do-i-need-to-use-this-integration.

Thanks!

### Additional info

_No response_

TriageBot — Needs refinement

### 2026-06-26

**Type:** documentation

**Section check:**
- ✅ What's missing/unclear: both missing prerequisites described with specific section URL
- ❌ Definition of done: not explicitly stated (added in rewrite)

**Ambiguity / scope notes:**
- Title grammar: "requirement" should be "requirements"; title lacked the integration name
- Empty bullet point between the two requirements was a formatting artifact

**Cross-references:**
- https://www.elastic.co/docs/reference/integrations/aws/billing — valid
- (docs.aws.amazon.com/redacted) — valid

**Next step:** Rewritten above

> Generated by [Gh Aw Issue Triage](https://github.com/elastic/docs-content/actions/runs/28259686180) for issue #7127 · 35.7 AIC · ⌖ 9.7 AIC · ⊞ 9.1K · [◷](https://github.com/search?q=repo%3Aelastic%2Fdocs-content+is%3Aissue+%22gh-aw-workflow-call-id%3A+elastic%2Fdocs-content%2Fgh-aw-issue-triage%22&type=issues)

Start with the AWS Billing integration page at https://www.elastic.co/docs/reference/integrations/aws/billing and locate the “What do I need to use this integration?” section. Add the us-east-1 region requirement and the requirement to enable AWS billing alerts, preserving the CloudWatch reference; done means both prerequisites appear in that section.

Written by the indexing model from the issue text.