I see another answer while preparing this (I will leave my full reply @Fox as you appear to have linked “Install only” IMG-filename which won’t work.)
Does you Updater offer Local update? Look Updater 3 dot menu top right.
If yes you can download an OTA_PACKAGE from /api/v1/FP4/official/ … currently 3 lines down look for
"url": "https://ota.ecloud.global/official/FP4/e-3.0.2-a14-20250627504416-official-FP4.zip",
One option download the file with a PC to the phone’s SD card. Then Local update is expected to allow to navigate to the file and then update.