Hello Faymlor,
welcome in the UiPath Community.
You want to use late binding, but this is not possible inside a invoke code activity. Here a tiny tip how to realize the using of late binding.
But this is not the right way, as @LevKushnir described. Please visit the UiPath Academy and take the great course SAP Automation. This course is for everybody interested in automating SAP Business Processes within SAP WinGUI.
Best regards
Stefan