You can cancel your developer plan using the steps below. This will not delete your account! After cancelling the developer plan, your account will then have a hobby plan.
Log in to your Bitrise account.
Click your avatar in the top right corner and select Account settings from the dropdown menu.
Scroll down the left side menu and select Billing.
In the Plans section, select HOBBY.
Click Change plan.
In case of cancellation, your resources will be available till the end of your subscription period.