How to implement app-ads.txt for your admob

I spent a couple of days to take care of the app-ads.txt issue for my admob applications.
So, I would like to share how to implement app-ads.txt file for your admob applications.

You don’t have to follow the google instruction, it makes you confused.

the instruction on google, https://support.google.com/admob/answer/9363762?hl=en makes me a little confusued.
It says that I have to create the app-ads.txt file using the Authorized Sellers for Apps specification provided by the IAB. But there is no sample code and it makes me more confused. You can ignore the instruction and follows my instruction if you didn’t get the add-ads.txt for your admob application.

Requirements

• Domain, Hosting: You have domain and hosting to upload your app-ads.txt file.
• Play Store App’s website information should be updated with your domain.

To get app-ads.txt, login to Admob.

You can get the app-ads.txt from ADMOB website. Once you login to your admob site, please display all of your apps screen.
on the top of the page, there is two tabs, one is app and the other one is app-ads.txt. Please click app-ads.txt tab.
In this tab, you can check the app’s app-ads.txt status. If you didn’t setup app-ads.txt the status is grey. if there is any issue with app-ads.txt, the status is red. Otherwise, if there is no issue with app-ads.txt, it is green.

Copy app-ads.txt

On the right side, there is a HOW TO SET UP APP-ADS.TXT button. Once you click the button, you can see a code as below:

google.com, pub-XXXXXXXXX, DIRECT, XXXXXXXXXXXXXX

You can simply copy the code and paste on your txt editor and save it as app-ads.txt, Please do not change the txt file format. Defalut format will be ANSI and it is OK. In my case, I changed the the txt format to UTF-8 and I got an error so I changed the format back to ANSI and it is OK now. After that, you have to upload your app-ads.txt to you root of your domain. Verification process will takes a day at least. Once it is validated, the status of your app-ads.txt will be changed to green color. Congratulations!