Search engines favor high-quality content that makes sense and is readable. The keyword quantity in your content should be of a certain percentage, roughly about 2-4% of your overall content. This means you should use your keywords 2-4 times per 100 words.
One thing to keep in mind: Avoid excessive keyword entry. It is best to write about your products and category information in a very natural way, not focusing on injecting your keywords repeatedly.
You can also try one of these third-party keyword density checkers to make sure that your text doesn't contain too many (or too few) keywords. The right keyword density ensures optimal performance in search results:
Keyword Density Checker by SEO Review Tools
Online Keyword Density Tool by Small SEO Tools
Keyword Density Checker by Copywritely