How to update the description(which has existing image) using REST API 3

Hi ,
I am looking for updating description using jira rest api v3. The issue description already has image in it. I am trying to edit only text in the description but I don’t want to lose the image. I used edit issue api as blow. Text fields are getting updated, but image is broken after this call and attachment also got removed.
PUT
url : https://api.atlassian.com/ex/jira/{jirasiteid}/rest/api/3/issue/TES-1
Request Payload
{ "update": { "description": [ { "set": { "version": 1, "type": "doc", "content": [ { "type": "paragraph", "content": [ { "type": "text", "text": "added discription updated 2", "marks": [ { "type": "strong" } ] } ] }, { "type": "mediaSingle", "attrs": { "layout": "align-start" }, "content": [ { "type": "media", "attrs": { "url": "https://yourdomain.atlassian.net/rest/api/2/attachment/content/10007", "type": "external", "width": 4032, "height": 3024 } } ] }, { "type": "paragraph", "content": [ { "type": "text", "text": "above is a sample image? updated 2" } ] } ] } } ] } }

The url in the media I got it from the Jira issue update webhook , in the attachment field.

The main goal for me is to sync Jira ticket description with our application. we have enabled 2 way syncing. Even though we don’t support adding images in our application for description, but we don’t want to lose the images added in Jira while syncing.