

Please don't use all caps!
I didn't use it
You did for the topic title.
Can you help me configure my XML correctly?
<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE properties SYSTEM 'http://java.sun.com/dtd/properties.dtd'>
<properties>
<entry key="config.default">./conf/default.xml</entry>
<entry key='database.driver'>com.mysql.jdbc.Driver</entry>
<entry key='database.url'>jdbc:mysql://localhost/traccar?zeroDateTimeBehavior=round&serverTimezone=UTC&allowPublicKeyRetrieval=true</entry>
<entry key='database.user'>root</entry>
<entry key='database.password'>root</entry>
<entry key='notificator.types'>web,mail,sms</entry>
<entry key='notificator.sms.manager.class'>org.traccar.sms.HttpSmsClient</entry>
<entry key='sms.http.url'>http://XXX.XX.XXX.XX:3000/api/sendText?token=5222fc86259745a085467c28e21bd080</entry>
<entry key='sms.http.headers'>Content-Type: application/json X-Api-Key: 5222fc86259745a085467c28e21bd080</entry>
<entry key='sms.http.template'>
{
"session": "default",
"chatId": "{phone}@c.us",
"text": "{message}"
}
</entry>
</properties>
It seems that you are using inexistent keys (http.headers doesn't exists). I think you could test with this configuration :
<entry key='sms.http.authorizationHeader'>X-Api-Key</entry>
<entry key='sms.http.authorization'>{here goes your token}</entry>
I recommend you to change your API token, and your mysql user/password as them have been exposed here (even when here is not disclosed any ip address).

I did it, I'm receiving alerts via WhatsApp! Thank you!
All my connections are via VPN.
Is it possible to configure the Traccar XML to send notifications via Waha?