Upgrade 3.4.2 to 4.0.3: In frontend only PostgreSQL available

[MyKey0815]

I upgrating my UCS 4.3-3 from Zabbix 3.4.2 to 4.0.3. Now I want open the frontend with

http://192.168.100.92/zabbix/setup.php

In the "Configuration DB Connection" I can only select "PostgreSQL". But I use MySQL
root@ucs100092:/etc/apache2/conf-available# mysql --version
mysql Ver 15.1 Distrib 10.1.37-MariaDB, for debian-linux-gnu (x86_64) using readline 5.2

I can see in the zabbix_server.log that data come in and mails will send, when a Issue occurs. So only the frontend is not working now.

What can I do? Can someone help me with some tipps?

[MyKey0815]

Solution in my case was:

apt-get install php-mysqlnd

Now the frontend is working again