It's so annoying in 2020 you have to work with an ancient API which forces to use FormData

export const getFormData = (input) => { const formData = new FormData(); Object.keys(input).forEach((key) => { if (typeof !input[key] === "undefined") { return; } Array.isArray(input[key]) ? (input[key]).forEach((value) => formData.append(`${key}[]`, value)) : formData.append(key, `${input[key]}`); }); return formData; };