kotlin, map a class to another class

I'm creating an API rest and I need it when I do "find ALL" instead of fetching all the data, I just fetch a few. With Java I did it this way:

 @GetMapping(value = "/pagina")
    public ResponseEntity<Page<PersonFindDTO>> findAll(
            @RequestParam(value = "page", defaultValue = "0") Integer page,
            @RequestParam(value = "linesPerPage", defaultValue = "24") Integer linesPerPage,
            @RequestParam(value = "order", defaultValue = "ASC") String order,
            @RequestParam(value = "orderBy", defaultValue = "name") String orderBy) {


        var person = personService.findAll(page, linesPerPage, order, orderBy);

        var personFindDto = person.map(PersonFindDTO::new);

        return ResponseEntity.ok().body(personFindDTO);
    }

With Kotlin, I'm trying this way:

   @GetMapping(value = ["/{companyId}/{active}"])
    override fun findAll(
            @RequestParam(value = "page", defaultValue = "0") page: Int,
            @RequestParam(value = "linesPerPage", defaultValue = "24") linesPerPage: Int,
            @RequestParam(value = "order", defaultValue = "ASC") order: String,
            @RequestParam(value = "orderBy", defaultValue = "tradeName") orderBy: String,
            @PathVariable companyId: Long, @PathVariable active: Boolean): ResponseEntity<Page<Any>> {

        val lp = service.findAll(page, linesPerPage, order, orderBy, companyId, active)?.let {
            it.map {
                fun LegalPerson.toLegalPersonMPage() = LegalPersonMPage(id = it.id,
                        tradeName = it.tradeName, companyName = it.companyName, cnpj = it.cnpj)
            }
        }
        return ResponseEntity.ok().body(lp)
    }

But the return is always empty. Could anyone help? Please.