Add Dash and API tabs for Per-record CNAME flattening

Author: RebeccaTamachiro

src/content/docs/dns/cname-flattening/set-up-cname-flattening.mdx

@@ -9,7 +9,7 @@ head:
 
 ---
 
-import { Render } from "~/components"
+import { Render, TabItem, Tabs } from "~/components"
 
 :::note
 
@@ -37,12 +37,31 @@ Accounts on paid plans can choose to flatten all `CNAME` records on their domain
 
 ## Per record
 
-Accounts on paid plans also have the option to flatten specific `CNAME` records. This operation is currently only supported via API.
+Accounts on paid plans also have the option to flatten specific `CNAME` records.
+
+<Tabs syncKey="dashPlusAPI"> <TabItem label="Dashboard">
+
+1. Log in to the [Cloudflare dashboard](https://dash.cloudflare.com/login) and select your account and domain.
+2. In **DNS** > **Settings**, make sure that **CNAME flattening for all CNAME records** is turned off.
+3. Go to **DNS** > **Records** and find the CNAME record you would like to flatten.
+4. Select **Edit** and turn on the **Flatten** option.
+5. Select **Save** to confirm.
+
+:::note[Unavailable flatten option]
+For the following cases, **Flatten** will not be available:
+- The record is at the [zone apex](#for-your-zone-apex).
+- The record is already proxied, which means it will be flattened by default.
+- **CNAME flattening for all CNAME records** is turned on, which means you cannot override it per-record.
+:::
+
+</TabItem> <TabItem label="API">
 
 With the available [API endpoints](/api/operations/dns-records-for-a-zone-create-dns-record), specify the following for each `CNAME` record in the request body:
 
 ```txt
 "settings": {
   "flatten_cname": true
 }
-```
+```
+
+</TabItem> </Tabs>