Cancel Roblox Premium in Settings (desktop app or web browser)
- 1
Log into the account where the membership was purchased.
- 2
Click the Gear icon in the upper right.
- 3
Open Settings and select Subscriptions.
- 4
Click the "Cancel Renewal" button and follow the prompts to confirm.
- 5
Stay on Settings > Subscriptions to check the renewal date and expiration date Roblox shows for the membership.
Source: en.help.roblox.com — the provider's own documentation for these steps.