Some reasons why your Spritz bottle is not working are a loss of pressure, clogs in the nozzle or even a damaged or detached tube.
Check the nozzle of the Spritz bottle by removing the nozzle and rinse it with some warm water to dislodge an dried residue or even mineral deposits.
You can also take a needle or a pin to gently clear the opening of the Spritz bottle.
Also check the tube itself and the bottom of the tube and ensure the bottom of the tube is not clogged or the tube itself is not clogged.
You can run a thin wire or needle through the tube if it has access from the bottom of the tube which can allow you to clear a clogged tube.
You can also soak the nozzle in some vinegar or CLR to descale the tube and loosen any debris or deposits.
Also check for any possible damage to the suction tube or see if the tube is detached from the bottle.
Also you can try priming the Spritz bottle by pumping the nozzle while it's submerged in water.
Another thing you can do is to shake the Spritz bottle gently or hold the Spritz bottle upside down which can redistribute the liquid and could restore the pressure.
If the Spritz bottle nozzle is severely clogged or damaged, you may have to replace the entire spray top or just replace the whole Spritz bottle.
To prevent issues with the Spritz bottle you should clean the nozzle regularly to prevent clogs from building up and store the Spritz bottle upright to prevent leaks and ensure that the Spritz bottles tube is submerged properly in the liquid.
And also be aware that certain liquids like those liquids containing resins are more prone to clogging.
If the spray from your Spritz bottle is weak, the seals may also be worn or a spring that is inside the trigger mechanism of the Spritz bottle may be broken or out of place.