<dependency>
  <groupId>org.webjars.npm</groupId>
  <artifactId>bootstrap</artifactId>
  <version>4.3.1</version>
</dependency>

implementation 'org.webjars.npm:bootstrap:4.3.1'

implementation("org.webjars.npm:bootstrap:4.3.1")

libraryDependencies += "org.webjars.npm" % "bootstrap" % "4.3.1"

@Grapes(
  @Grab(group='org.webjars.npm', module='bootstrap', version='4.3.1')
)

<dependency org="org.webjars.npm" name="bootstrap" rev="4.3.1" />

[org.webjars.npm/bootstrap "4.3.1"]

'org.webjars.npm:bootstrap:jar:4.3.1'