Exports in local coordinates

[Midkhat]

I am working on a project where the export is required in local grid.
The cameras data comes in GDA2020 and I have a set of GCPS in MGA2020 and corresponding in Local Grid, something like that:
MGA:
682963.000,6290736.000,751.946
688160.278,6297960.584,1000.842
680000.000,6290000.000,1000.000
LOCAL:
14586.825,15604.061,5751.946
15163.831,24486.096,6000.842
12464.381,13408.995,6000.000

I know it can be done with setting TOWGS84 Helmert 7-parameters in Agisoft, but struggle to figure out how I get these 7 parameters. Could someone direct me to how I can build a python script to define these parameters from the GCPs?

At the moment I solve that with transforming rasters and point clouds from MGA to Local with affine transformation, which generally works OK, but there are benefits of exporting in local directly from Agisoft in our project.