Login in Pio app is only possible when you have been added as a user by an Admin. See details in this article How to add new Users in Pio. Also, here is an overview of Pio User roles.
If you have forgotten your pincode, contact your Warehouse Manager or someone with Admin access to Pio app to have it reset.
Reset user passcode
Login to Admin Dashboard and navigate to Users > select the requested user > click the three dots for options > select 'Edit details'.
Click the '4-digit passcode' field and enter the new pin.
Click 'Save' to exit the flow and share the new pincode with the requester.
Reset user password
If you have Admin access to your Pio app, and access the Pio Admin Dashboard on a laptop, you will have to sign in using your email and your password.
Click the 'Forgot password?' link to receive an email with instructions on how to set a new password.
You will receive an email shortly, with a link to reset your password.