How to protect the data on the phone when handing over for repair?

Question

Google

The battery "died" on the phone, the phone (on Android) does not turn on, I want to send it in for repair and replace the battery. No passwords have been set. How can I protect data on my phone from leakage? Naturally, there will not be a SIM card there, there were no banking applications, but there are different data - photos, videos, etc. In principle, I give it to the service that I already used, but still I don’t want the data to end up in random hands after the repair.

Answer 1

Ask to change the battery in your presence. Many services do this. Accordingly, you will see that no one copies anything from the phone.
If the phone does not turn on at all, then it is impossible to protect data from leakage in the service.

Answer 2

Turn on the phone and delete all data
I don’t think that anyone in the service needs pictures of your cat

Answer 3

No way. That is why it is advised not to store anything "such" in the phone, or at least keep "it" on a flash drive.