Safari on iPhone cannot hide its address bar for games. Add this site to your Home Screen and start it from there: it then runs full screen, in landscape.
This runs the 2003 RTS engine source release. Game data is not included: select your own original Generals disc images (both discs, .bin/.cue or .iso) or your installed game folder. Files are read on this device and stored in this browser only — nothing is uploaded.
On iPhone: put the disc images in the Files app (e.g. iCloud Drive), then select all of them at once.
Choosing a folder: your browser asks whether to "upload" the files. That is the standard wording of the browser; this site only reads them on your device and sends nothing.