I am using springBoot 2.7.7 with maven and when I paste ModelMapper dependency in my pom.xml, it shows error saying: Dependency 'org.modelmapper:modelmapper:' not found
Run mvn clean install; then if the problem persists i'd suggest you look into you maven folder for a settings.xml file.
It's usually located on %USERPROFILE%/.m2
If you have a file like that, maven may look for dependencies on other repositories addresses instead of the default one.
So just delete or rename it. run maven again and restore the file back.