Fix authentication options request body

Author: chrisfisher

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@authsignal/browser",
-  "version": "1.12.4",
+  "version": "1.12.5",
   "type": "module",
   "main": "dist/index.js",
   "module": "dist/index.js",

src/api/passkey-api-client.ts

@@ -58,14 +58,15 @@ export class PasskeyApiClient {
 
   async authenticationOptions({
     token,
+    challengeId,
     useCookies,
   }: {
     token?: string;
   } & AuthenticationOptsRequest): Promise<AuthenticationOptsResponse | ErrorResponse> {
     const response = await fetch(`${this.baseUrl}/client/user-authenticators/passkey/authentication-options`, {
       method: "POST",
       headers: buildHeaders({token, tenantId: this.tenantId}),
-      body: JSON.stringify({}),
+      body: JSON.stringify({challengeId}),
       credentials: useCookies ? "include" : "same-origin",
     });