If you are facing installation failure because of some prerequisite check either from OEM or Database side, there is way to ignore the check from OEM side. But it’s best practice to resolve all the checks.
Now to do so, you have to install the OEM binaries in Software-Only method. You can check Installing OEM 13.4 [Silent Install] : Software-Only Method.
After that, make copy of stopPrereqOnDemand.properties file. It’s located in {ORACLE_MIDDLEWARE_HOME_LOCATION}/install/requisites/properties/ directory.
For my OEM silent install on Oracle Cloud, I faced prerequisites checks about Database Edition. To fix it, I edited the stopPrereqOnDemand.properties file and went to configure my EM.
id_check_db_is_enterprise_edition=TRUE
If you face any issue just change the prerequisites check value from FALSE to TRUE and proceed with the configuration.