If you have forgotten your password, you can click the "Forgot Password" button under the password box on the login modal. You can open this modal by clicking the 'Login' button on any page if you're logged out of a Rollbit account.
If you can not find the link to reset your password in your email make sure to check your Junk/Spam folder.
If you have already set a password on your account you can head to the Settings page and enter your old password along with a new one to change it to.
If you signed up with another method such as Twitch, Steam or MetaMask then you might need to set a password. To do this you can just enter the same password in the old password and new password fields within your Settings page.