The first step is to create a new dLocal merchant account here: https://merchant.dlocal.com/sign_up
After submitting information, you will receive a confirmation link from firstname.lastname@example.org in your email address. Verify the link, and you are all set to access the panel.
Access the merchant panel through https://merchant.dlocal.com/login using the email and password you set when signing up. You are ready to operate in the Sandbox environment.
Remember to change your password after your first sign in. You can do that through Settings >> Change my password.