FTPManager is a free app which allows you to access and upload files to an FTP server from your iPhone. To download it, open your iPhone's {"smallUrl":"https:\/\/www.wikihow.com\/images\/5\/55\/Iphoneappstoreicon.png","bigUrl":"\/images\/thumb\/5\/55\/Iphoneappstoreicon.png\/30px-Iphoneappstoreicon.png","smallWidth":460,"smallHeight":460,"bigWidth":"30","bigHeight":"30","licensing":"<div class=\"mw-parser-output\"><p>I edited this screenshot of an iOS icon.\n<\/p><p>License: <a rel=\"nofollow\" class=\"external text\" href=\"http:\/\/en.wikipedia.org\/wiki\/Fair_use\">Fair Use<\/a><br>\n<\/p><\/div>"} App Store, then do the following:  Tap Search  Tap the search bar. Type in ftpmanager and tap Search  Tap GET to the right of the orange-and-white "FTPManager" heading. Enter your Apple ID or Touch ID when prompted. Once FTPManager finishes downloading, tap OPEN in the App Store, or tap the orange FTPManager app icon on your iPhone's Home Screen. It's in the top-right corner of the screen. This option is near the top of the page. Doing so opens a form for a new FTP connection. If your FTP server requires you to log in with a username and password, enter them in the "LOGIN AS..." section at the bottom of the page. It's in the top-right corner of the screen. Doing so saves your FTP server and adds it to the main FTPManager page. You can only have one FTP server at a time on the free version of FTPManager. To delete an FTP server, tap Edit in the top-left corner, tap the red circle to the left of your FTP server, and tap the trash icon. Tap the server's address below the "CONNECTIONS" heading in order to do so. This will connect to your FTP server. Keep in mind that this only works for servers for which you have permission to upload:  Tap ＋ at the bottom of the screen. Tap New Folder or Blank File  Name your folder or file, then tap Save or Create While there isn't much that you can upload from your iPhone, photos and videos are still feasible to upload:  Tap the Photo Library option on the FTPManager main page. Tap Allow when prompted to let FTPManager access your photos. Select an album. Tap Edit  Select a photo or a video. Tap Copy to at the bottom of the screen. Tap your FTP connection. Select a folder, then tap Save

Summary:
Download the FTPManager app. Open FTPManager. Tap ＋. Tap FTP. Add a username and password. Tap Save. Select your FTP server. Create files in the FTP server. Upload photos to the FTP server.