The make and model of your toilet is usually located under the toilet tank lid.
To find the make and model of your toilet carefully remove the toilet tank lid and set it gently on the floor, with the bottom facing up.
Look closely on the bottom side of the toilet tank lid for the manufacturer name or a number on the bottom side of the water tank lid.
Sometimes you may need to lookup the numbers on google search to find the make and model of your toilet.
Some toilets it can be hard to find the make and model of the toilet.
But most times the make and model of the toilet will be under the toilet tank lid although I've seen some toilets have the make and model inside the tank itself on the back side.
But most toilets including my toilet I have now in my house has the make and model located under the toilet tank lid.
If you can't find the make and model of your toilet but need parts for the toilet then you can take a picture of the inside parts and the parts should be easily found in most plumbing stores.
Most toilet parts are interchangeable but some toilets have different handles, fill valves etc.