The word "skills" (as you've used it) is plural here. Therefore, you need to change the following words to plurals:
one
this
Communication skills happen to be one of the most important skills required in business. Because with this skills, I can explain my ideas, opinions, and also get feedbacks.
2 answers
Communication happens to be one of the most important skills required in business. Because with this skill, I can explain my ideas, opinions, and get feedback.