Help with rest command

I have a android tablet that run WallPanel. I trying to control it with Home Assistant so I can turn the screen on and off with HTTP command.

But not sure if I do it right. I have try some code but nothing happend.
The last code I did try was

    url: 'http://192.168.x.x:2971/api/command'
    payload: '{"wake": true}'
    method: 'post'
    url: 'http://192.168.x.x:2971/api/command'
    payload: '{"wake": false}'
    method: 'post'

Put POST instead of ‘post’. If it still doesn’t work, somebody else will help you out

Thanks for the replay but no change after I have replace ‘post’ with POST

Do you find the solution?