Yes, for example, by using moderated regression analysis with one or more product (interaction) variables. See, e.g.,

https://www.spss-tutorials.com/spss-regression-with-moderation-interaction-effect/

https://www.youtube.com/watch?v=VEN4h98Ys7k

The process can be automated with the Process Macro:

https://www.processmacro.org/index.html#/

Yes, as Christian Geiser implies, moderation is just another word for interaction effects.

Yes, it is possible. https://phantran.net/running-the-moderation-analysis-in-spss-using-process/#:~:text=You%20can%20run%20a%20moderation%20analysis%20through%20the,command%2C%20and%20then%20do%20a%20simple%20slopes%20analysis.