Add to Home Screen
On a computer this is one click. On iPhone Apple only allows it through Safari → Share — there is no Install button Apple lets apps show.
Chrome, Firefox, and Edge on iPhone cannot add websites to the home screen. Apple only allows this in Safari.
Tap Copy this page link above
Open the blue Safari app
Paste the link in the address bar and go
Then follow the Safari steps below
That mini-browser also cannot add to Home Screen.
Or tap ⋯ → Open in Safari if you see it.
Do these 4 taps in Safari
Stay in Safari on this page
Bottom toolbar: ← → □↑ □ 📖
Tap the Share button □↑ (square with arrow up) in the middle of the bottom bar
In the share sheet, scroll down (past AirDrop, Messages, Mail) until you see Add to Home Screen
Tap Add to Home Screen, then tap Add
1. Scroll the share list all the way down
2. Tap Edit Actions… (or Edit)
3. Find Add to Home Screen → tap +
4. Tap Done, open Share again — it should appear
Install from Chrome
Open this page in Chrome
Tap menu ⋮ (top right)
Tap Install app or Add to Home screen
Chrome / Edge
You said desktop worked — use the install icon in the address bar, or menu → Install SupplierAdvisor.