The openSUSE repos which the TO shows in his first post, does not contain the package mdatp. Hence the error message that the package is not found.
The link in the first comment explains that mdatp is only available for SLES. You need to use the SLES repo as explained there (openSUSE is officially not supported even if it may work).
Comment 7 shows the correct SLES repo and installation of mdatp which sucessfully finishes. The procedure in this comment followed the installation instructions from the Microsoft link.