problems with PHP, Phpmyadmin, Roundcube

I try everything. please help.
PHP is important. I can't even run WordPress website.

Server: megaservicenyc.com (Debian Stretch) ISPConfig 3.1.11
State: ok (0 unknown, 0 info, 0 warning, 0 critical, 0 error)

Ok
The state of your Hard-Disk space is ok [More...]
Your virus protection is ok [More...]
Your Mail queue load is ok [More...]
Your Server load is ok [More...]
All needed services are online [More...]
Your system is up to date. [More...]
The System Log is O.K. [More...]

Status of Services (Server : megaservicenyc com)
Web-Server: Online
FTP-Server: Online
SMTP-Server: Online
POP3-Server: Online
IMAP-Server: Online
DNS-Server: Online
mySQL-Server: Online