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@Embbnux Ji will do . The below are my observations.

In the message-sync service ((https://platform.ringcentral.com/restapi/v1.0/account/~/extension/~/message-sync) I do see the image links with uri as "https://media.ringcentral.com/..." But when I go to the individual conversation page, I don't see any call getting fired from the react app to retrieve the image. I also don't see any error in the console log . Ideally to display a call should be invoked to media.ringcentral.com. Please suggest.

Hi @Ext 45211 Can you help to collect HAR file and log, and sent to us? I guess this is a network issue to read image.
To collect HAR and log:
1. Open chrome developer tool
2. Reproduce the issue to send image in SMS
3. Go to chrome developer tool's network panel, right click at request to save all as HAR with content
4. Go to chrome developer tool's console panel, right click at log to save all as file
And create case at https://developers.ringcentral.com/support/create-case and share the HAR and log after you receive a email.