Hi~ Not sure what APM version you are on but I found this: https://techdocs.f5.com/kb/en-us/products/big-ip_ltm/releasenotes/related/relnote-supplement-bigip-13-0-0.html
497100 : APM Migrates to Google reCAPTCHA API Version 2.0
Component: Access Policy Manager
Symptoms:
Google introduced reCAPTCHA API v2 in December 2014. The v2 API will not work with API key pair generated for v1 API. With APM migrating to reCAPTCHA v2, the key pair that works with previous releases of the APM will stop functioning after upgrade.
Google recommends sites that are using v1 API to register new keys and upgrade to v2. (See https://developers.google.com/recaptcha/docs/faq)
Conditions:
When key pair generated for v1 API is used in the reCAPTCHA configuration.
Impact:
Users will not be able to log in.
Fix:
N/A
Behavior Change:
Before upgrade, admin is required to register a new key pair with Google. After upgrade, the "secret" and "site key" fields on the reCAPTCHA admin UI are populated with the old keys. Replace the old keys with the new keys obtained from Google.
Furthermore, the "Verification URL", "Challenge URL", and "Noscript URL" fields are populated with the URLs for Google reCAPTCHA v2 service, not those that were specified before the upgrade. If a virtual server has been configured for v1 verification using HTTPS, the virtual server needs to add client side SSL profile and the "Verification URL" field should point to the virtual server.
Moreover, the "CAPTCHA Theme" is obsolete and is replaced by v2 CAPTCHA render configuration parameters with the following default values:
Data Theme = Light
Data Type = Image
Data Size = Normal