How_to ? Jira trigger REST APi with payload: Jira "update data"

First post here as a Jira user :slight_smile:

problem #1)
We want to have Jira ticket action to do REST API call with Jira “update” text as API parameter. The REST server will convert text to .json then start another process.

problem #2)
To complete this, would like to our process to make an “update” to Jira ticket with text eg. Jira REST API call

Any creative solution would be most appreciated. Super thanks for a response.