what the colleague said above is an explanation of what you should do if you want your wallet not to be lost. The thing that is often done is when you register in mew and you open it in metamask so you forget that what you need to take care of of course is the mew key not in the metamask. because if you forget and only remember metamask then you will lose your wallet.

When you register yourself in mew use a JSON file instead of using a passkey, because it works the same as what you would do in metamask so you don't need to know the passkey but you only need to save the JSON file in a safe place and a password to open it. or you connect directly to your metamask the most important thing is that you don't forget the password and if it gets lost you also have the "Seed Phrase" file to repair, where the file is stored in a place that you can save properly.