Yes used coffee grounds to help grass to grow.
The used coffee grounds helps grass grow and thrive by by encouraging microbes in the soil to grow which helps the soil to use nitrogen which is also helpful for the grass to grow and thrive.
Just make sure to not leave the coffee grounds on the grass itself because it could harm the grass but instead make sure after you sprinkle the coffee grounds on the grass to water the grass with a hose to help wash any coffee grounds off the grass and into the soil.
Each spring I will aerate my lawn and then pour coffee grounds onto the lawn and then water the grass and my grass has started growing better and staying greener.
I also use some other grass fertilizer as well.
Used coffee grounds are also good for vegetable gardens and some flowers as well.
So instead of throwing used coffee grounds in the trash put them into an old coffee container and then use them as fertilizer.