change accepted extent format

app.ts

@@ -71,10 +71,10 @@ app.post("/buy", async (req, res, next) => {
         //TODO validate this properly
         let txDetail = await getTransactionDetail(req.body.txHash, req.body.user);
 
-        let extent: Array<Array<number>> = JSON.parse(txDetail.description).extent as Array<Array<number>>;
+        let extent: number[] = JSON.parse(txDetail.description).extent as number[];
         let dataFileId: string = Date.now().toString();
         
-        let dataCommand = CHAIN4ALL_RASTER_CLIP_SCRIPT_PATH + ' ' + extent[3][1] + ' ' + extent[3][0] + ' ' + extent[1][1] + ' ' + extent[1][0] + ' ' + dataFileId;
+        let dataCommand = CHAIN4ALL_RASTER_CLIP_SCRIPT_PATH + ' ' + extent[0] + ' ' + extent[1] + ' ' + extent[2] + ' ' + extent[3] + ' ' + dataFileId;
         console.debug(dataCommand);
 
         const { stdout, stderr } = await asyncExec(dataCommand);