My MacBook Air touchpad stopped clicking

If Intel, reset NVRAM and SMC, restart, and try again. Or restart, if Apple silicon. You might need to use an external keyboard and mouse. If that reset or restart doesn’t clear this, then the problem could be a damaged or stuck trackpad, a swelling battery, or some other hardware issue. Contact Apple Support and discuss your options.

https://appletoolbox.com/why-cant-my-macbook-pro-trackpad-click/

Look for the switch on side of touchpad and make sure it’s turned on, it will not click if the tab/power button is off.