Accidentally removed device from Lost Mode on iPhone
How to remove if you accidentally remove device on iPhone
[Re-Titled By Moderator]
iPhone 14 Pro Max, iOS 18
I don’t entirely understand your question, but I’ll try to make the most out of it.
If you accidentally removed your device from the Lost Mode state, you can still reenable it.
But if you accidentally removed your iPhone from Find My, that would disable Activation Lock and thus allowing anyone to setup and use your iPhone for themselves. There is no way to undo that.