How Access react.js Chat Web Application Messages and files in Microsoft 365 Omnichannel

Question

I am expecting to handle all chats and files in omnichannel from the react.js web application.

Here i am not aware how to handle web page message conversation in to omnichannel

I found some reference following by

https://learn.microsoft.com/en-us/dynamics365/customer-service/developer/omnichannel-api-reference

But it executes in omnichannel, not from an external web application. I need some reference to handling web chat conversation