Can I tether my iPhone 14 Pro to Glinet Flint?

Yes. Please try.

Here is the docs

Here is the docs for 4.x

That doesn’t work, I don’t get a trust this computer message ! I don’t have a cable that has usb A, only usb C and an adapter !

You should have a USB-A lightening cable.

Otherwise, you have to connect the router to your phone’s hotspot via wifi repeatger.