I found the solution !!!
The documentation on
https://api.pulseway.com/
show example using /assets method accessed the following way :
https://api.pulseway.com/v2/assets
This is false !!!!
You need to use your instance name like this :
https://mycompany.pulseway.com/api/v2/assets
Impossible to authenticate on the rest api
i copied the curl example replacing username and password
i tried with the php example.
i tried with my custom library, etc.