Firstly this is for High Sierra

i've already tried this step  :

Character Accent Menu doesn't appear anymore in macOS Sierra

• Add a second language like French in Settings -> Keyboard -> Input Source

• When i type defaults read -g ApplePressAndHoldEnabled in a Terminal i got a 1

• Go into Settings, Keyboard and make sure the Key Repeat slider is set to Slow and the Delay Until Repeat slider is set to Short.

Even if i restart the Accent Menu doesn't appears.

And this is my Mac  :

macOS High Sierra | version 10.13, MacBook Pro (Retina, 15-inch, Mid 2015)

Firstly, this is for High Sierra

I've already tried this step:

Character Accent Menu doesn't appear anymore in macOS Sierra

• Add a second language like French in Settings -> Keyboard -> Input Source

• When I type defaults read -g ApplePressAndHoldEnabled in a Terminal I got a 1

• Go into Settings, Keyboard and make sure the Key Repeat slider is set to Slow and the Delay Until Repeat slider is set to Short.

Even if I restart the Accent Menu doesn't appear.

And this is my Mac:

macOS High Sierra | version 10.13, MacBook Pro (Retina, 15-inch, Mid 2015)