I have created a record-triggered flow to work with an field update change in an approval process. The flow is fired off a child object called Subsidy Request with a currency field called Requested Amount. The parent object for it is Subsidy Budget and it has a currency field called Budget Amount. When the flow is triggered off the child and meets conditions, I need to update the Budget Amount in the parent object by subtracting the Requested Amount from the Budget Amount (basically a formula). I have not been able to do this, but know little about Flows.
I have tried to Get the Budget Amount and save it to a formula resource that I created doing a Get Records action, but when I try to use that in the Update Records action below and save, I get an error:
Get_Budget_Amount (Get Records) - The sObject variable $Record has object type LISI_Subsidy_Request__c, which doesn't match the object selected for lookup.
Am I doing something that is even possible with flow?