Hello Jean Charles,
I would recommend creating a subfolder for this purpose and specifying its name in the Data Management section, then make sure to set full permissions (type 777) for this subfolder specifically.
I remain available.

You mean in this section ? 

Cause here I can't change the directory...

Thanks for your help

Hello Jean Charles,
no, the folder can be created either in Step 5 - Export ---> Upload to the internet, by entering the Destination folder and creating a subfolder inside, but its permissions must be set through any control panel you have available to manage your hosting space.

Hi Eric, 

Thank you, but what I have to do, to see it working in that case ?

Thanks

Hello Jean Charles,
I will try to recap the steps again:

1) Enter your Destination folder, the main folder used to publish the website
2) Create a subfolder, calling it for example acces-ecriture
3) Use your hosting control panel to set full permissions for reading/writing for this subfolder (type 777)
4) Enter the name of the subfolder in the Data Management section in Step 5 - Export ---> Upload to the internet ---> Parameters
5) Publish the website

Hi, 

Are you sure with a 777 at the root folder the website could be secur ?

Hello Jean Charles,
it is not the root folder that should have these permissions, but rather the subfolder you have created for the purpose of becoming the folder with writing access.

This one ?

Hello Jean Charles,
unfortunately I am not sure what the screenshot is showing.
What is the root folder you are using, and have you created a new subfolder inside of it to be used for this purpose?