If you ask me to answer this in just two words, I will say: original content. That would be the first thing i would say if you ask me anyway. But here i am writing a detailed information

To get approval
Just post the original video that you made, make sure they get several views (1000); then it is quite applied.

Make sure your videos and channels are not banned by Google Adsense content, so you will be fine.

A list of prohibited content can be found at the following link: Prohibited Content.

I think you mean how to activate monetization on your YouTube account, right?

It’s rare for people to ask, as approved by the Google YouTube channel, and you see lots of questions on the blog and site approval. To shorten, you can approve the YouTube channel in just 2 hours. Yes, seriously, I have done that before. This is something to do.

Visit www.youtube.com/account_monetization.
Click the account authorization option in the sidebar.
Now upload the video and you must activate the ad in settings.
That’s it!

https://naijaforward.com.ng/2019/06/22/how-to-get-adsense-approval-for-youtube-100-legit