Hey @admdiegolima,
I have just given this a quick go and for me it is working in a quick test, I have created a generic Basic auth credential that looks like this…
Then in my workflow I have added a Set node before my HTTP Request node that sets a username and sets the password to the workflow execution id so it is something that changes.
Now in my test http request node I am just firing the request off to webhook.site to see what the value is and I can see there that they are being set correctly.
Below is my test workflow and the results can be seen here, Can you give the same thing a go and see if you get the same issue like this?