If you have someone's phone number, you can easily find their Zalo account. If you don't want to reveal your Zalo account to others, follow the steps below, applicable on Xiaomi Redmi Note 11 Pro 5G or other smartphones.
Firstly, go to the search bar and enter your mobile phone number to search. If you haven't hidden your phone number yet, Zalo will display your name as shown in the image below.

To hide it, go to the Settings section with the gear icon, then go to Privacy settings:

Next, tick the Accept friend requests section and swipe to turn off the Phone number part.

To ensure your method is correct, try checking if your phone number has been hidden by searching for it again.

Wishing you all success!