Understanding simple app flow

Hi All

I am trying to recreate the following:

In the main app SPA file (index.html)

I fetch data from an API end point.

The data gets returned as an object.

I then save the data to a variable “Mydata” that is available to all the pages of the app.

Then add some more data to “Mydata”.

Later in the app I access “Mydata” either as an object or in some case individual value in the object.

Note: I can not use local storage or cookie storage.

I know how to do this as plain JS want to learn how to do this via Wappler

Thanks