Since you have mentioned Dropbox, I am assuming you are talking about Windows VPS. In order to transfer files to Windows VPS, you need to do the following.
On your Windows VPS:
Download Filezilla Server:
https://filezilla-project.org/download.php?type=server
Once the download is completed, do the following settings on your VPS.
- Disable the Windows Firewall Temporary.
Here are the configurations you need to setup for Filezilla Server:
# Click on the Displays the user accounts dialog icon.
# In General, click on Add and add a username: BHW (You can add anything else if you want) and hit Ok. Check Enable Account and add a password as per your wish.
# In Shared Folders, click on Add and select Desktop (You can select a particular folder as well if you want) and hit Ok. After that, check Read, write, delete and append for Files and check create, delete, list and +subdirs for directories. Now, make sure to select that new Desktop directory and then set it as home dir by clicking on the Set as home dir button. Once done, hit Ok.
Now, download Filezilla Client on your desktop:
https://filezilla-project.org/download.php
Quickconnect section of FileZila Client:
In the IP address, enter the IP address of your VPS, enter the username & password (leave the port section empty) that you have setup on Filezilla server and hit Quickconnect.
Boom! You are now connected from your PC to your VPS using Filezilla successful, now you can drag and drop all your files from your PC to VPS.
If you want to transfer from your VPS to your PC then follow the exact same process.
Hope this helps.