url params with fileUpload in nodejs

const response = await fetch(`http://${serversIP}/upload/${encodeURIComponent(saveMediaPath)}`, {
   method: 'POST',
   body: formData,
   headers: {
     'Content-Type': 'multipart/form-data',
   }
 }); 

const storage = multer.diskStorage({
   destination: (req, file, cb , err) => {
       let savePath = imagesDir
       //console.log("its",req.params.filePath)
       if(req.params.filePath!="startPoint"){
           savePath = path.join(imagesDir,req.params.filePath)
       }
       cb(null, savePath); // Save all files to the 'images' directory
   },
   filename: (req, file, cb) => {
       cb(null, Date.now() + path.extname(file.originalname));
   }
});

i am trying to send the destination as a url param

in order to save it where it needs to be but almost always , the first time i am fetching fails but after the first time works flawless , any ideas

i have tried --> send it as header --> append it in the json

i dont know how to solve it , and i cant find something usefull on the internet any ideas would be more than welcomed