am actually interacting with a SOAP webservice which makes a POST request and returns a response with status 200 and an xml file, but when I want to catch that message I receive the following response: "SyntaxError: Unexpected token <in JSON at position 0 at JSON.parse () at XMLHttpRequest.onLoad "

service:

emision(body): Observable<any> {
    let httpOptions = {
      headers: new HttpHeaders({
        
        'Authorization': "*********",
        'Action': "postproduct",
       
      })
    };
    return this.http.post('/api/******',
      body, httpOptions)
}

subscribe:

 this.mainService.emision(obj).subscribe(
                  (value) => {
                    console.log(value);
                   
                  },
                  (error) => {
                    console.log(error);
                    console.warn(
                      "ERROR CONEXION"
                    );
                  }
);

Although when I enter the console and then in network I can verify that the response is with status 200 and a response in xml format, when I want to catch the response it generates an httpResponseError with the following message "SyntaxError: Unexpected token <in JSON at position 0 at JSON.parse () at XMLHttpRequest.onLoad "