Append new data to existing feature class using Load Data in ArcGIS Pro

I am trying to append new rows of data for a feature class that shares the exact same fields (column headers and types) but wasn’t able to using Load Data in ArcGIS Pro. In ArcMap, you could easily hit reload table cache and the table will update by calling the CSV that it uses to plot the feature class. But it seems very difficult to do it in ArcGIS Pro.

When using "Load Data" function, I tried 2 options:

1. Input schema must match target schema – the input table has the exact same header with new data to be appended. It kicked Error 000466.
2. Use the Field Map to reconcile schema differences – Same input table, but I also double checked in the Field Map section to make sure the properties of each output field is the same as what is in the feature class now. This step gave the Error 001156.

I might not be exactly sure how to use this tool.