I solved the problem. For those who have this problem, I am writing below. There is a problem with this topic on your page ( https://websitetoapk.com/docs/creating-keystore-for-signing.html )
You have a code like this on your page :
keytool -genkey -keyalg RSA -alias myalias -keystore newkeystore.keystore -storepass yourpassword -validity 36000 -keysize 2048
this is an incorrect code.
the correct code is as follows :
keytool -genkey -keyalg RSA -alias myalias -keystore newkeystore.jks -storepass yourpassword -validity 36000 -keysize 2048
Here is where you need to pay attention to in this code :
When you create the keystore code in this way, you can install the application via the google play console.