Add error message on pop-up cancel

Author: tiurin

src/utils/manage.ts

@@ -183,7 +183,12 @@ export async function stopLocalStack(
 
 export async function openLicensePage() {
 	const url = new URL("https://app.localstack.cloud/settings/auth-tokens");
-	await env.openExternal(Uri.parse(url.toString()));
+	const openSuccessful = await env.openExternal(Uri.parse(url.toString()));
+	if (!openSuccessful) {
+		window.showErrorMessage(
+			`Open LocalStack License page in browser by entering the URL manually: ${url.toString()}`,
+		);
+	}
 }
 
 async function showInformationMessage(