docs: update release notes

Author: yyforyongyu

docs/release-notes/release-notes-0.18.3.md

@@ -58,6 +58,36 @@ commitment when the channel was force closed.
   send payment stream context, or automatically at the end of the timeout period 
   if the user provided `timeout_seconds`.
 
+* The [SendCoinsRequest](https://github.com/lightningnetwork/lnd/pull/8955) now
+  takes an optional param `Outpoints`, which is a list of `*lnrpc.OutPoint`
+  that specifies the coins from the wallet to be spent in this RPC call. To
+  send selected coins to a given address with a given amount,
+  ```go
+      req := &lnrpc.SendCoinsRequest{
+          Addr: ...,
+          Amount: ...,
+          Outpoints: []*lnrpc.OutPoint{
+              selected_wallet_utxo_1,
+              selected_wallet_utxo_2,
+          },
+      }
+
+      SendCoins(req)
+  ```
+  To send selected coins to a given address without change output,
+  ```go
+      req := &lnrpc.SendCoinsRequest{
+        Addr: ...,
+        SendAll: true,
+        Outpoints: []*lnrpc.OutPoint{
+            selected_wallet_utxo_1,
+            selected_wallet_utxo_2,
+        },
+      }
+
+      SendCoins(req)
+  ```
+
 ## lncli Additions
 
 * [Added](https://github.com/lightningnetwork/lnd/pull/8491) the `cltv_expiry`
@@ -68,6 +98,18 @@ commitment when the channel was force closed.
   command returns the fee rate estimate for on-chain transactions in sat/kw and
   sat/vb to achieve a given confirmation target.
 
+* [`sendcoins` now takes an optional utxo
+  flag](https://github.com/lightningnetwork/lnd/pull/8955). This allows users
+  to specify the coins that they want to use as inputs for the transaction. To
+  send selected coins to a given address with a given amount,
+  ```sh
+  sendcoins --addr YOUR_ADDR --amt YOUR_AMT --utxo selected_wallet_utxo1 --utxo selected_wallet_utxo2
+  ```
+  To send selected coins to a given address without change output,
+  ```sh
+  sendcoins --addr YOUR_ADDR --utxo selected_wallet_utxo1 --utxo selected_wallet_utxo2 --sweepall
+  ```
+
 # Improvements
 ## Functional Updates