Adding Time Together Within Data

I have a Data Type of “Work Orders”.
These work orders have a field type called “Due Date”.
This due date needs to be calcuated by taking the Work Order Created Date and adding time on to it.
There is a separate data type called SLA, which has fields of 4hrs & 24hrs.
The idea is that when a new work order is created, a time is picked and this combines the created date and the SLA time to create the due date.

I can’t figure it out!, Any help would be great,
Thank you

Capture d’écran, le 2024-05-15 à 16.42.22

Current date/time +hours: Current SLA Number of hours (4 or 24)