delete data from flash in MDBT42?

Hello ,
as I understadn I can use about 40kb~ of memory in the MDBT42
I have code that save into RAM and then move it to the flash

require("Storage").write("test",JSON.stringify(ScanResault));
   GetData = JSON.parse(require("Storage").read("test"));
   ScanResault.length=0;
   console.log("Clear Array finsih");
   console.log(    ScanResault.length);        

I can see the RAM is clear without a problem
then I send this information to another devcie and after a while I want to clear the flahs
but I'm unable to do this
this is the command I'm using :

require("Storage").erase("test");

but it doesn't work

why?