Design for javaFX application

I'm currently developing an application with javaFX using FXML Windows. the scope of the application is the following:

Get User Inputs (e.g. credentials) -> use these credentials to retrieve information using Web Services API calls -> use the collected information to either create a file or visualize in a table.

Currently, I am using the Main class to launch each FXML Window, return the info to the Main class and pass it to the next FXML Window and so on (e.g. Main -> FXMLWindow_1 -> Main -> FXML_Window_2 -> Main -> ...).

My question is is this correct from a design / workflow stanpoint? Or would it be better / same to launch each FXML Window sequentially from the previous one (e.g. Main -> FXMLWindow_1 -> FMXLWindow_2...)?