You may call Labtalk script from Python to add text at the specified position. Try the example Python code below:
import originpro as op
graph = op.new_graph()
gl = graph[0]
gl.lt_exec(f'label text_to_add') ## add label to the layer.
go = gl.label('text') ## get the text object
go.set_int('left', 2840) ## set text position
go.set_int('top', 5000)
go.set_int('attach', 0) ## attach the text object to layer
gl.lt_exec('pfit2l') ## fit the page to layers
Here Labtalk command label is called from Python to place the label. Please refer to the page on the label command.
https://www.originlab.com/doc/LabTalk/ref/Label-cmd
James