@JvmDefault and how add compiler option

@Target([AnnotationTarget.FUNCTION, AnnotationTarget.PROPERTY])
annotation class JvmDefault

Specifies that a JVM default method should be generated for
non-abstract Kotlin interface member.

Usages of this annotation require an explicit compilation argument to
be specified: either -Xjvm-default=enable or
-Xjvm-default=compatibility.

with -Xjvm-default=enable, only default method in interface is generated for each @JvmDefault method. In this mode, annotating an
existing method with @JvmDefault can break binary compatibility,
because it will effectively remove the method from the DefaultImpls
class.

with -Xjvm-default=compatibility, in addition to the default interface
method, a compatibility accessor is generated in the
DefaultImpls class, that calls the default interface method via a
synthetic accessor. In this mode, annotating an existing method with
@JvmDefault is binary compatible, but results in more methods in
bytecode.

Removing this annotation from an interface member is a binary
incompatible change in both modes.

Generation of default methods is only possible with JVM target
bytecode version 1.8 (-jvm-target 1.8) or higher.

@JvmDefault methods are excluded from interface delegation.

https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.jvm/-jvm-default/index.html

if you use gradle then add this parameter to gradle script

https://kotlinlang.org/docs/reference/using-gradle.html

for example add this to gradle:

kotlinOptions {
    freeCompilerArgs = ['-Xjvm-default=compatibility']
}

otherwise if you use Kotlinc command line compiler add -Xjvm-default=compatibility after your command in command line