Hi dagvasuren,
Welcome to the Apple Community.
Wondering if your phone returns a message that it is disabled when you try to log-in,
OR
whether you put the iPhone into "Lost" mode.
Apple support have an article online
if a message says that your iPhone is disabled, learn what to do.
Says:
If you enter the wrong passcode on your iPhone Lock Screen too many times,
an alert will let you know that your iPhone has been disabled.
Wait for awhile, then try again.
Complete article: https://support.apple.com/en-au/HT204306
OR
If you put the iPhone into "Lost" mode:
This article from Apple Support: "Use Lost Mode in Find My iPhone on iCloud.com"
Says:
How to "Turn off Lost Mode on an iPhone, iPad, iPod touch or Apple Watch:
- In Find My iPhone on iCloud.com, click All Devices and then select the device that’s in Lost Mode.
- Click Lost Mode, click Stop Lost Mode and then click Stop Lost Mode again.
- You can also turn off Lost Mode by entering your passcode on the device.
Complete article: https://support.apple.com/en-au/guide/icloud/mmfc0f0165/icloud
Hope this helps :-)