handle validations onChanged

app/lib/screens/wallets/send.dart

@@ -110,25 +110,33 @@ class _WalletSendScreenState extends ConsumerState<WalletSendScreen> {
     final fromAddress = fromController.text.trim();
     toAddressError = null;
     if (toAddress.isEmpty) {
-      toAddressError = "Address can't be empty";
+      setState(() {
+        toAddressError = "Address can't be empty";
+      });
       return false;
     }
 
     if (toAddress == fromAddress) {
-      toAddressError = '"To" and "From" addresses must be different';
+      setState(() {
+        toAddressError = '"To" and "From" addresses must be different';
+      });
       return false;
     }
 
     if (chainType == ChainType.TFChain) {
       if (toAddress.length != 48) {
-        toAddressError = 'Address length should be 48 characters';
+        setState(() {
+          toAddressError = 'Address length should be 48 characters';
+        });
         return false;
       }
     }
 
     if (chainType == ChainType.Stellar) {
       if (!isValidStellarAddress(toAddress)) {
-        toAddressError = 'Invaild Stellar address';
+        setState(() {
+          toAddressError = 'Invaild Stellar address';
+        });
         return false;
       }
 
@@ -137,16 +145,23 @@ class _WalletSendScreenState extends ConsumerState<WalletSendScreen> {
       final Wallet? wallet =
           matchingWallets.isNotEmpty ? matchingWallets.first : null;
       if (wallet != null && wallet.stellarBalance == '-1') {
-        toAddressError = 'Wallet not activated on stellar';
+        setState(() {
+          toAddressError = 'Wallet not activated on stellar';
+        });
         return false;
       } else {
         final balance = await Stellar.getBalanceByAccountId(toAddress);
         if (balance == '-1') {
-          toAddressError = 'Wallet not activated on stellar';
+          setState(() {
+            toAddressError = 'Wallet not activated on stellar';
+          });
           return false;
         }
       }
     }
+    setState(() {
+      toAddressError = null;
+    });
     return true;
   }
 
@@ -196,6 +211,7 @@ class _WalletSendScreenState extends ConsumerState<WalletSendScreen> {
 
   void _selectToAddress(String address) {
     toController.text = address;
+    _validateToAddress();
     setState(() {});
   }
 
@@ -276,6 +292,9 @@ class _WalletSendScreenState extends ConsumerState<WalletSendScreen> {
                               color: Theme.of(context).colorScheme.onSurface,
                             ),
                         controller: toController,
+                        onChanged: (text) async {
+                          _validateToAddress();
+                        },
                         decoration: InputDecoration(
                             labelText: 'To',
                             errorText: toAddressError,