Class name "notifications_table" is not in StudlyCaps format
Classes in PHP are usually named in CamelCase.
In camelCase names are written without any punctuation, the start of each new word
being marked by a capital letter. The whole name starts with a capital letter as well.
Thus the name database provider becomes DatabaseProvider.
This method's name is shorter than the configured minimum length of 3 characters.
Even though PHP does not care about the name of your methods, it is generally a
good practice to choose method names which can be easily understood by other human
readers.
Classes in PHP are usually named in CamelCase.
In camelCase names are written without any punctuation, the start of each new word being marked by a capital letter. The whole name starts with a capital letter as well.
Thus the name database provider becomes
DatabaseProvider
.