React fine-uploader upload the file - reactjs

Question

I have a simple react app. I've added react-fine-uploader to it. I have a Flask server that accepts files and puts them into MongoDB database. The code for server looks like this:
from flask import Flask, render_template, request
from pymongo import MongoClient
import os
import time
from json import dumps, loads
app = Flask(__name__)
global index
map_dir = 'maps'
client = MongoClient(
'<connection_string>')
db = client.business
#app.route('/maps', methods=['GET'])
def process():
cursor = db.maps.find({}, {'_id': False})
maps = {'maps': []}
for doc in cursor:
try:
maps['maps'].append(doc['filename'])
except Exception:
pass
return dumps(maps)
#app.route('/map/<map_name>', methods=['GET'])
def get_map(map_name):
doc = db.maps.find_one({'filename': map_name}, {'_id': False})
return dumps(doc)
#app.route('/uploader', methods=['GET', 'POST'])
def upload_file():
if request.method == 'POST':
f = request.files['file']
parsed = loads(f.read())
filename = ''.join(f.filename.split('.')[:-1]) + str(index) + '.json'
parsed['filename'] = filename
try:
result = db.maps.insert_one(parsed)
return 'File uploaded successfully'
except Exception:
return 'Error while uploading a file'
if __name__ == '__main__':
global index
index = len(os.listdir('maps')) + 1
app.run(debug=True)
It works with standard HTML input form with specifying target as localhost:5000/uploader. Now I want my fine-uploader form to do the same. In code it looks like this:
const uploader1 = new FineUploader({
options: {
request: {
endpoint: "localhost:5000/uploader"
},
resume: {
enabled: true
},
retry: {
enableAuto: true,
showButton: true
}
}
});
And somewhere in the render() method I got: <Gallery uploader={uploader1} />
Now I can select file, but when it is selected the form tries to upload it and it fails. Server is running and I can see no request on him in the terminal. Is there something I am doing wrong?
#Edit I've enabled debug mode and it throws something like this into dev console:
Cross origin requests are only supported for protocol schemes: http, data, chrome, chrome-extension, https