Do not understand VRM-API behaviour

Dear Forum I requested succesfullly a token in the VRM API website, (without 2FA).
But any next request using this token fails due to unauthorized access response. I tried eg. list all access tokens, meteo data for my site and various others messages…
Tried application of the token with ’ at start and end, " at start and end, the bare list, as bearer and as token… Nothing is succesfull. Tried via Postman. Same behaviour…
Expect it is something trivial (again). But what do I do wrong…

this is a Postman message:
“success”: false,
“errors”: “No valid authentication scheme sent”,
“error_code”: “invalid_token”