In my kotlin app I have an endpoint GET /v1/money?accounts=... where accounts is a list with comma separated strings. I need to build a Wiremock stubbing where I’ll return that list in the response. But my variant doesn’t work:

portalWiremock.server().stubFor(
            get(urlPathMatching("/v1/money?accounts=.*"))
                .willReturn(
                    okJson(
                        """
                {
                    "trackingId": "abcde12345",
                    "accounts": ${'$'}{accountsList(request.queryParameter("accounts"))}
                }
                """.trimIndent()
                    )
                )
        )
...

fun accountsList(accountsParam: String?): String {
        val accounts = accountsParam?.split(",") ?: emptyList()
        val accountsJson = accounts.joinToString(",", "[", "]") { ""$it"" }
        return accountsJson
    }

Is there another way I should use? Is it possible in general to catch/return in that way?