Hi @DHAGZ ,
According to your description, I've made a test for your reference:
1\ Build an instant flow:

2\ Add this flow and add a button control and set its onselect property to:
Set(A,TEST35.Run().thevar)
3\ Add a button control and set its onselect property to:
Download(A)
Best Regards,
Wearsky
If my post helps, then please consider Accept it as the solution to help others. Thanks.