How to create user-movable objects in a web application

There is an application Fast Report Online Designer, I would like to recreate a publicly available free version of this product with open source for all users, as this is a quite useful tool that would simplify the work of many workers
Question: What ways can you recommend for developing a module with drag-and-drop objects (databands) for a web application?

I’m working on Python, planning to use Django for web development
I’ve already tried to figure out dragg and drow in JS, the concept looks similar to the truth, but it’s too complicated to implement (I’m not strong in JS knowledge)
Please suggest some options for implementation
Thank you!

PS:
Fast Report example:
https://www.fast-report.com:2015/razor/Home/Designer
example screenshot:
enter image description here