Click the Apple logo on the top left corner of your desktop and then choose "About this Mac". After that you will see the necessary information in the opened window.
Also, there is an exact number of your model on the bottom of your laptop. For example, for MacBook Air 13" 2015 the model number is A1466.
A2681- MacBook Air 13" (2022,M2)
A2442 - MacBook Pro 14" (2021)
A2485 - MacBook Pro 16" (2021)
A2141 - MacBook Pro 16" (2019)
A1707 / A1990 - MacBook Pro Touch Bar 15" (2016-2019)
A2337 - MacBook Air 13" (2020, M1)
A2179 - MacBook Air Retina 13" (2020)
A1932 - MacBook Air Retina 13" (2018-2019)
A2338 - MacBook Pro 13" (2020, M1)
A1706 / A1989 / A2159 / A2289 / A2251 - MacBook Pro 13" (2016-2020)
A1708 - MacBook Pro Non-Touch Bar 13" (2016-2017)
A1534 - MacBook 12"
A1369 / A1466 - MacBook Air 13" (2012-2017)
A1425 / A1502 - MacBook Pro Retina 13" (2012-2015)
A1398 - MacBook Pro Retina 15" (2012-2015)
A1278 - MacBook Pro 13" (Non-Retina, 2009-2012)
A1286 - MacBook Pro 15" (Non-Retina, 2009-2012)
A1370 / A1465 - MacBook Air 11"
Be careful when choosing the model of your device! It is very important!