Hi @bounouas ,
I've made a test for your reference:
1\I assume there is a collection
learCollect(ACollection,{Column1:"A",Column2:"B",Column3:"C"},{Column1:"A",Column2:"B",Column3:"C"},{Column1:"A",Column2:"B",Column3:"C"},{Column1:"A",Column2:"B",Column3:"C"})
2\Add a flow into the app





3\Modify the flow


4\Add a button and set it's OnSelect Property to:
'PowerAppV2->Createfile,CreateHTMLtable,Convertfile,Delay,Send...'.Run(JSON(ACollection))
5\Click the button and get the result:


Best Regards,
Bof