Bypass F5 ASM

If the ASM is properly configured, you should not be able to bypass it. If you can bypass it this would be considered either a misconfiguration or a defect.

The URL you reference is well known to me and requires a very specific configuration on the ASM. You would need to have the ASM configured to handle both JSON and form encoded data on the same URL (a highly specialized and unusual configuration to say the least). For most users this would be a misconfiguration, as a web application would normally either process JSON or form encoded data, possibly both on different URLs, but not likely both on the same URL.

If you are the administrator of the ASM it is fairly trivial to configure the BigIP to bypass the ASM for specific requests using Local Traffic Policies or iRules. As an end user this should not be possible.