Dockerfile: No package matches php

I am currently trying to make a Dockerfile with the Ubi-7-minimal Baseimage (This is a must do),
to make a Joomla-Dockerimage.
Problem is, that it always says that "No package matches php"
First, my Dockerfile (I know, the CMD is missing, but thats not the point)

FROM registry.access.redhat.com/ubi7/ubi-minimal 

EXPOSE 443 80

RUN rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY* 
RUN microdnf install epel-release

RUN microdnf install httpd 

RUN microdnf install php

In some suggestions, like here, but no success.
Another suggestion is, to first install epel-release, but while building, it just says nothing to do when running "RUN microdnf install epel-release".

Thanks in advance

Source: StackOverflow