Explanation:

Box 1: Inbound.
A set-variable policy to store the detected user identity.
Example:
<policies>
<inbound>
<!-- How you determine user identity is application dependent -->
<set-variable
name="enduserid"
value="@(context.Request.Headers.GetValueOrDefault("Authorization","").Split(' ')[1].AsJwt()?.Subject)" /> Box 2: Inbound A cache-lookup-value policy Example:
<inbound>
<base />
<cache-lookup vary-by-developer="true | false" vary-by-developer-groups="true | false" downstream-caching- type="none | private | public" must-revalidate="true | false">
<vary-by-query-parameter>parameter name</vary-by-query-parameter> <!-- optional, can repeated several times -->
</cache-lookup>
</inbound>
Box 3: Outbound
A cache-store-value policy.
Example:
<outbound>
<base />
<cache-store duration="3600" />
</outbound>
Box 4: Outbound
A find-and-replace policy to update the response body with the user profile information.
Example:
<outbound>
<!-- Update response body with user profile-->
<find-and-replace
from='"$userprofile$"'
to="@((string)context.Variables["userprofile"])" />
<base />
</outbound>
Reference:
https://docs.microsoft.com/en-us/azure/api-management/api-management-caching-policies
https://docs.microsoft.com/en-us/azure/api-management/api-management-sample-cache-by-key