I have this delete function that when user click it will push the id into delete array. User can delete multiple picture by click one by one icon trash. And to save thier commit changes about the delete item they have to click on the save button. But I have problem in sending the data in the form append.

output that I want to achieve is it will send the id the format like this

[64,65]

But currently it only send like this

64,65

my code

<a href="#javascript:;" onclick="deleteDoc('${e.doc.id}')"></a>

const deleteDoc = (id) =>{
    deleteDoc_temp.push(id);
}

const update = () => {

    let deleteDoc =  deleteDoc_temp; 

    let formData  = new FormData();
 
    formData.append('deleted_attachment', deleteDoc);
   
    for (var pair of formData.entries()) { console.log(pair[0]+ ', ' + pair[1]); }
}

How do I fix this problem to make sure that I can achieve output in append form like this ?

[64,65]