How to add a border to hyperlink with Fitz module?

I spent three hours experimenting this morning on this but I can't manage to make the border visible on a hyperlink within a pdf annotated with the python FITZ module. Any idea ? Thanks so much in advance !

import fitz

doc = fitz.open("test.pdf")
page = doc[0]

d = {'kind': 2, 'xref': 0, 'from': fitz.Rect(90, 240, 200, 270), 'uri': 'https://www.google.fr', 'id': ''}
page.insert_link(d)

lnk = page.first_link
while lnk:
    lnk.set_border(width=1.0, dashes=[], style='S')
    lnk.set_colors(stroke=(1,0,1))
    lnk = lnk.next

doc.saveIncr()