Add dedicated page for setup with requirements and API example

Author: RebeccaTamachiro

src/content/docs/aegis/configuration-options/index.mdx

@@ -2,7 +2,7 @@
 title: Configuration options
 pcx_content_type: navigation
 sidebar:
-  order: 2
+  order: 5
   group:
     hideIndex: true
 ---

src/content/docs/aegis/index.mdx

@@ -19,7 +19,7 @@ Leverage dedicated IPs to improve your origin security and implement Zero Trust.
 
 Cloudflare Aegis provides dedicated egress IPs (from Cloudflare to your origin) for your layer 7 [WAF](/waf/) and <GlossaryTooltip term="content delivery network (CDN)">CDN</GlossaryTooltip> services, as well as [Spectrum](/spectrum/). The egress IPs are reserved exclusively for your account so that you can increase your origin security by only allowing traffic from a small list of IP addresses.
 
-Both [BYOIP](/byoip) and Cloudflare-leased IPs are supported by Cloudflare Aegis. Refer to [Setup](TBD) for details.
+Both [BYOIP](/byoip) and Cloudflare-leased IPs are supported by Cloudflare Aegis.
 
 ***
 

src/content/docs/aegis/setup.mdx

@@ -0,0 +1,32 @@
+---
+title: Setup
+pcx_content_type: how-to
+sidebar:
+  order: 2
+  group:
+    hideIndex: true
+---
+
+You can control Aegis enablement on your zones via API.
+
+## Requirements
+
+- The Aegis zone setting endpoint is only available within Cloudflare accounts that own leased IPs, or accounts to which a BYOIP prefix has been delegated. If you wish to use Aegis for zones that do not meet this criteria, contact your account team.
+- Each Aegis pool can consist of either IPs from a [BYOIP prefix](/byoip/) or Cloudflare-leased IPs. A single dedicated egress pool cannot contain both BYOIPs and leased IPs.
+
+## Steps
+
+1. Contact your account team to get the ID for your dedicated egress pool.
+2. Make a `PATCH` request to the [Edit Zone Setting](/api/resources/zones/subresources/settings/methods/edit/) endpoint:
+- Specify `aegis` as the setting ID in the URL.
+- In the request body, set `enabled` to `true` and use the ID from the previous step as `pool_id`.
+
+```bash
+--data '{
+  "id": "aegis",
+  "value": {
+    "enabled": true,
+    "pool_id": "<YOUR_EGRESS_POOL_ID>"
+  },
+}'
+```