i'm trying to put a SIM card in iphone 5s ios 12.5.7

That means the iPhone is locked to a carrier that is different from the one for the SIM card you are trying to use.

You would need to contact the carrier the iPhone is locked to, to get it unlocked.

click here ➜ How to unlock your iPhone for use with a different carrier - Apple Support

The iPhone 5s is classified as Obsolete by Apple, so there is no support for the product.

As the message notes......

Ask your carrier to send you a new SIM card to see if that might help, or if the phone is locked to another carrier, you must first contact that other carrier and ask them to unlock the phone.

Do you know who the original carrier was?