Thanks great helping, It’s working for
https://example.com/u/USERNAME.json Where i can find myself by replacing example.com (by the forum url) and USERNAME (by my username)
but for
https://example.com/u/by-external/EXTERNAL_ID
When i tryed the same logic : Replacing example.com by the forum url and replacing EXTERNAL_ID by : 1,2,3 and some random value.