Unity banner dont show

My app (VIETNAM) use Interstitial and banner, but only Interstitial work fine, banner dont show in my app ( my app more than 1.000 download and ~400 active / day). How cai can fix it ?
Thank you very much ( and sr about my English).
Can search my app on Google play with keyword “tra cuu phu tung” (HD-P)

Hi hd-p,

Do you meet this each time when you test? Banner ads usually have a low fill rate, and you can try to use an American VPN to test for several times. Banner ads have a higher fill rate there. Unity Ads has a global fill rate of greater than 95%, but some regions outside of America and Europe that might have smaller ad pools won’t always have ads available. It’s important to check whether ads are available before showing ads to your users.