Custom Script for updating field value depending on value of another field

While creating new item or editing existing item I want Material Request type of an Item to be depending on its Item Group.

Please help me with custom script while adding or editing new item.

Thanks
Regards

Welcome to ERPNext,

This may help Not Found

The above link you will find here Frappe Framework Tutorial

Check out these https://erpnext.org/docs/user/manual/en/customize-erpnext/custom-scripts/custom-script-examples

Lots of instructional videos too Session 4: Scripting DocTypes - I - YouTube