diff --git a/server.ts b/server.ts
index 4ce4161..614f330 100644
--- a/server.ts
+++ b/server.ts
@@ -639,9 +639,10 @@ app.post('/api/admin/settings', authenticateToken, requireAdmin, (req: Authentic
   res.json({ success: true, settings: db.settings });
 });
 
-app.get('/api/admin/test-asaas', authenticateToken, requireAdmin, async (req: AuthenticatedRequest, res: Response) => {
+app.post('/api/admin/test-asaas', authenticateToken, requireAdmin, async (req: AuthenticatedRequest, res: Response) => {
   try {
-    const result = await AsaasService.testConnection();
+    const { asaasApiKey, asaasEnvironment } = req.body || {};
+    const result = await AsaasService.testConnection(asaasApiKey, asaasEnvironment);
     res.json(result);
   } catch (err: any) {
     res.status(500).json({ success: false, message: err.message || 'Erro ao testar conexão Asaas' });
diff --git a/src/components/AdminDashboard.tsx b/src/components/AdminDashboard.tsx
index c41e7f3..63f9104 100644
--- a/src/components/AdminDashboard.tsx
+++ b/src/components/AdminDashboard.tsx
@@ -128,7 +128,15 @@ export default function AdminDashboard({ token }: AdminDashboardProps) {
     setAsaasTestResult({ loading: true, success: null, message: 'Testando conexão com Asaas...' });
     try {
       const res = await fetch('/api/admin/test-asaas', {
-        headers: { 'Authorization': `Bearer ${token}` }
+        method: 'POST',
+        headers: {
+          'Content-Type': 'application/json',
+          'Authorization': `Bearer ${token}`
+        },
+        body: JSON.stringify({
+          asaasApiKey: settings?.asaasApiKey,
+          asaasEnvironment: settings?.asaasEnvironment
+        })
       });
       const data = await res.json();
       setAsaasTestResult({
diff --git a/src/services/asaas.ts b/src/services/asaas.ts
index a98e458..b6cfffe 100644
--- a/src/services/asaas.ts
+++ b/src/services/asaas.ts
@@ -24,22 +24,26 @@ export class AsaasService {
   /**
    * Test the connection to Asaas API
    */
-  public static async testConnection(): Promise<{ success: boolean; message: string; environment: string }> {
-    const apiKey = this.getApiKey();
-    const env = loadDb().settings?.asaasEnvironment || 'sandbox';
+  public static async testConnection(customApiKey?: string, customEnv?: string): Promise<{ success: boolean; message: string; environment: string }> {
+    const apiKey = customApiKey || this.getApiKey();
+    const env = customEnv || loadDb().settings?.asaasEnvironment || 'sandbox';
+    const apiUrl = env === 'production' ? 'https://api.asaas.com/v3' : 'https://sandbox.asaas.com/v3';
     
-    if (!apiKey) {
+    if (!apiKey || apiKey.trim() === '') {
       return { 
         success: false, 
-        message: 'Chave de API (API Key) não foi configurada.',
+        message: 'A chave de API (API Key) não foi definida ou está em branco.',
         environment: env
       };
     }
 
     try {
-      const response = await fetch(`${this.getApiUrl()}/customers?limit=1`, {
+      const response = await fetch(`${apiUrl}/customers?limit=1`, {
         method: 'GET',
-        headers: this.getHeaders()
+        headers: {
+          'Content-Type': 'application/json',
+          'access_token': apiKey.trim()
+        }
       });
 
       if (response.ok) {