Get history of change of custom fields(eta + reason) and send data automatically through api

[Tushar Anand]

My use case - I want to find the number of times a ticket's ETA is changed and what was the reason mentioned for that particular change. ETA will change after giving the reason only. Once the eta and its reason is submitted, both the things will be saved as a version history corresponding to my ticket.

For eg.

1. Go to Ticket Id -> XYZ-1122

2. ETA (Date field) -> 10/11/21

3. Reason to Change ETA (Descriptive) -> xyzxyz

4. Click on save

5. Map these changes to Ticket Id -> XYZ-1122 (Automatically)

6. ETA (Date field) -> 20/11/21

7. Reason to Change ETA (Descriptive) -> abcd

8. Click on save

9. Map these changes to Ticket Id -> XYZ-1122 (Automatically)

10. Result will be - 
XYZ-1122 : {{10/11/21 , xyzxyz},{20/11/21, abcd}}