Grafana login page problem

I can’t login grafana localhost.
localhost:3000 I show login page but e-mail or username and password is not valid.
Can you help me please?

Note: I signup with

did you try the default username and password for new local grafana instance?
username: admin
password: admin

If you want to login with your account you have to enable that in your ini file.

Thank you. Well done

I am having problems accessing the login page of grafana as in the attached image.
Grafana is installed on Raspberry 3b + with debian. The grafana service is started.
You can help me?
Thank you