You can lock your account immediately with the EMERGENCY LOCK feature in SETTING.
On the app version
Step 1: Click on your Profile icon -> Settings


Step 2: Go to Emergency Lock
Scroll down and click on the Emergency lock at Security and click “Emergency lock” -> choose the reason you want to deactivate your account as below

Step 3: Choose the reason for locking

Step 4: Select “LOCK MY ACCOUNT” and confirm again

Your account will be deactivated.

Note: You can contact support to reactivate your account later.