In this video I demonstrate how to test for the assumption of homogeneity of regression slopes and then address a possible approach for dealing with a violation of that assumption (using Hayes Process macro).
The data for this video can be downloaded here: https://drive.google.com/file/d/1BArQ_wlQjvxH1oWqzVWciWxgHvBc4TAh/
You can obtain a copy of the Process macro: https://www.processmacro.org/download.html
For more detail on how to use Process to test and describe the interaction between a multicategorical predictor and a continuous moderator, see this presentation: https://www.youtube.com/watch?v=IG-FnhvTud4