JWT Problem 503 gateway

hi dear ,
i follow this topic to create JWT :

but i have this problem 503 gateway error :
https://meet.myhost.com/http-bind?room=example&token=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJjb250ZXh0Ijp7InVzZXIiOnsiYXZhdGFyIjoiaHR0cHM6Ly9saXZlLmVsYWJpYi5jb20vaW1hZ2VzL3dhdGVybWFyay5wbmciLCJuYW1lIjoiSm9obiBEb2UiLCJlbWFpbCI6Impkb2VAZXhhbXBsZS5jb20iLCJpZCI6ImFiY2Q6YTFiMmMzLWQ0ZTVmNi0wYWJjMS0yM2RlLWFiY2RlZjAxZmVkY2JhIn19LCJhdWQiOiJ0TjJFM09ERXlaamhrT1dRellXUXlOamRrWmpNdE1HUmhaQzAwWldSa0xUaGlPVFEiLCJpc3MiOiJ0TjJFM09ERXlaamhrT1dRellXUXlOamRrWmpNdE1HUmhaQzAwWldSa0xUaGlPVFEiLCJzdWIiOiJsaXZlLmVsYWJpYi5jb20iLCJyb29tIjoiKiJ9.myFed6ZvQL3SNMQ42Fv2MKd8ajsmoxorB8xy9dGPqPw

What is the error in prosody?