In Expert mode, create a new action with the following parameters:
Name
Enter Set Checklist as the name of the new action.
Method
Select the PUT method.
Default connection
Select the connection with the current instance.
REST path.
Enter the following REST path.
/rest/api/2/issue/{issueIdOrKey}
REST path parameter
For the REST path parameter issueIdOrKey, select the field Issue key.
Action body
Enter an action body like the following one. For more indications on how to configure the action body to update a Checklist custom field, visit the Checklist documentation.