to install the pwa you must upload the files and folders of the pwa to the root folder, in addition to this you must copy the content of the tags.txt file inside the tag head of the page where you want to install the pwa.

to update the cache you must change the content of the variable "CACHE_SITE" found in the sw.js file (in the first line)

the content of the pwa messages can be found in the /js/pwa.js file, looking for "installMsg.innerHTML"

Thanks for buying :)