The noun praise can be countable or uncountable. In more general, commonly used, contexts, the plural form will also be praise. However, in more specific contexts, the plural form can also be praises e.g. in reference to various types of praises or a collection of praises.

Does praise have plural form?

The plural form of praise; more than one (kind of) praise.

What is the plural of complement?

The plural form of complement is complements.