Welcome to the Microsoft Q&A Platform. Thank you for reaching out & I hope you are doing well.
I understand that you would like to configure Web Application Firewall exclusion lists
These configurations are available to App Gateway WAF SKU with WAF Policy attached to it.
They may not be available for legacy WAF configuration.
Refer : Upgrade to Azure Application Gateway WAF policy
This is also documented in the wiki you have shared.
Please make sure you are using WAF Policy and then try to add the exclusion you'd like.
Kindly let us know if this helps or you need further assistance on this issue.
Thanks,
Kapil
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