Q.How do I treat a grass fungus
I have a grass fungus that looks foamy. Here is a link to a picture of the fungus https://www.city-data.com/forum/attachments/austin/111477d1368202967-fungus-st-augustine-grass-20130508_171014.jpg
Do you know what this is and how to treat it?
This is probably not a fungus, but the nefarious spittle bug. Here's some information: https://www.gardeningknowhow.com/plant-problems/pests/insects/spittlebug-control.htm
To be sure, you can dig up a sample, including grass and soil, and take it to the local Extension Service. This link will help you locate one: https://www.gardeningknowhow.com/extension-search/