Encoding problem when sending a request using RestTemplate

Sending a request using RestTemplate

var emailDto = new EmailDto();
email.setBody(DATA_TEXT);
HttpHeaders headers = new HttpHeaders();
Charset utf8 = Charset.forName("UTF-8");
MediaType mediaType = new MediaType("text", "html", utf8);
headers.setContentType(mediaType);
var httpEntity = new HttpEntity<>(emailDto , headers);
//restTemplate.getMessageConverters()
//   .add(0, new StringHttpMessageConverter(Charset.forName("UTF-8")));
var response = restTemplate.exchange(
ResponseEntity<String> response= restTemplate.exchange(
        emailPath,
        HttpMethod.POST,
        httpEntity,
        String.class);

DATA_TEXT - here is a piece of html code that I'm trying to send in a request

public static final String DATA_TEXT =

            "style='margin:0;padding:0;'> " +
" " +
"
 
 " +
" " +
"
 
 " +
"
 
 " +
"
Текст авпвапва вар о пор ораоа про прп" +
"
" +
"
" +
"
 
 " +
"my.com " +
"
 ";

When sending a request, it returns the following error: org.springframework.web.client.RestClientException: No HttpMessageConverter for ru.ocpiouserbacktest.model.EmailDto and content type "text/html;charset=UTF-8"

In the file Pom.xml specified

<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-web</artifactId>
</dependency>