How does Admob pays me for the add revenue my app has earned?

AdMob begins processing payments after the end of the calendar month in which they are earned. Their processing time is approximately two to three weeks. You will receive an email notifying you when payment processing has begun. This happens on the date that funds are removed from your AdMob account and is the date recorded in the Account Summary page of the Account tab.

In order for the processing to begin, you must meet the threshold for the method of payment you have selected.

It is $20 if you selected PayPal and $100 if you selected ACH/Wire. You must meet these thresholds to be eligible for payment. If your total payable earnings are less than the threshold amount, AdMob rolls over your earnings to the following month

you can also read more about this on
https://support.google.com/admob/checklist/2998383?hl=en&ref_topic=3445812&vid=1-635793364425853593-3832223615

For more details refer to

https://support.google.com/admob/topic/2745447?hl=en&ref_topic=2792286&vid=1-635793364425853593-3832223615