If your mist spray bottle is not working it can be due to a clogged nozzle or broken mechanism that pumps the liquid.
If your mist spray bottle has an on and off part on the nozzle you may have the on and off part of the nozzle in the off position or partially off position.
To fix a mist spray bottle that is not working you can try adding some hot water to the mist spray bottle and then try spraying.
You can also run the nozzle under some hot water and spray.
If that does not work and the mist spray bottle is still not working you can add a bit of dish soap into the mist spray bottle and spray and keep spraying until it clears up.
You can also use some Oxiclean in it and even soak it in Oxiclean to help clean it.
Also if your mist spray bottle is overfilled it can cause issues with the mist spray bottle due to uneven internal pressure.
Clogs in continuous spray bottles often result from residue buildup, mineral deposits from hard water, or thick product formulations that aren't well-suited for the spray bottle.