From the PAM that placed in the private subnet, when the AWS policy configuration is set, it seems PAM communicates with the sts.amazonaws.com. In order to communicate with sts.amazonaws.com, is it possible to through a specific proxy server. For example, in the below flow, PAM through the "Proxy Server A" to communicate the sts.amazonaws.com.
CA Privileged Access Manager 3.x (PAM)
There is not the expected feature in PAM.