Agent Link Parameter - Where can I get these parameters?

I have found other similar information such as assetDescriptors, assetInfos, metaItemDescriptors and valueDescriptors through the HTTP APIs (Pic 1), but I cannot find any APIs related to the additional parameters Agent link (Pic 2). I mean how does the Web know these parameters to show up? Get it from the server or create the client side? Thanks for help!

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Pic 1.


Pic 2. Add “Agent Link” to an Asset, then click Add Parameter.