Create an FTP account in Plesk

With FTP you upload files using a program such as FileZilla.

Here's how

1. Go to Websites & Domains and click FTP (FTP Access) next to your domain.
2. Click Add an FTP Account.
3. Enter a name and password and choose the folder this account has access to.
4. Click OK.

Connect with: server yourdomain.be, port 21 with explicit TLS (FTPES), your FTP name and password.