In this guide I intend to show how to raise the API to 31, but previously for those of us who still have limited free accounts, an alternative to be able to compile the APK without file limits in asset.
It is a 2 in 1 guide, each one carries what is useful to him.
as we know, when you want to compile with more than 5 MB of assets, we will get the notification.

what is proposed is to eliminate the files and assign them in the separate blocks with the name. (applies to images, audios, ect)
Then we just compile the APK as usual
Now it will be necessary to have the program (APK Easy Tool 1.6) comes in a portable version
once downloaded, in my case, the directory creates a folder called APK to have the file that I just compiled.
then we execute the apkeasytool and we go to browse > we select the APK and click on Decompile
when finished, at the bottom we can see what it says (SDK 30) we open the decompile directory
FILES: In the ASSETs folder we simply load the files (images, audio, …) which will be loaded by blocks
API: With any text editor we open the apktool.yml file and change the value to 31
now we open the AndroidManifest.xml file in the same way, in front of all the
<Activity
we place android:exported=“true” respecting the spaces, the same with the
<receiver
You can already see that the SDK increased to 31, now we compile the APK and send it to the mobile along with our android.keystore file to convert it to AAB and be able to sign it
on the mobile device we will need 2 apps APKtoAAB and Zipsigner
open the APKtoAAB load the APK and convert it to AAB
We open the ZipSigner and look for the directory where our AAB is
Then we go to the 3 dots and select My Keys > Register keystore
we select our android.keystore and it will ask us for a password, we place (android)
in Key/mode we select androidkey and give the button Sign the file.
We wait for the process to finish and that will be all.
We would already have our ABB with API 31 and exceeding the limit of 5MB of assets.