Export report with api power bi

I am trying to get data of my report through API REST.

https://docs.microsoft.com/es-es/rest/api/power-bi/reports/exportreport

Which has a button to test the API filling the report Id, it is not working, it return an answer code "404" and I don't know why, because it seems so simple.

I tried to do the same with Export Report in Group, filling the information and after a long time processing, it return an answer code "500"

Someone knows what is happening? because I have no much experience with this, and I didn't find information on internet.

Thanks!!!