Asynchronous execution of a loop: how to make it synchronous - spring

Question

spring-boot-starter-parent 3.0.0
It may be important. Anyway, under the hood:
<spring-framework.version>6.0.2</spring-framework.version>
import lombok.Synchronized;
...
#Service
#RequiredArgsConstructor
public class RequestService {
#Synchronized
public void scrape() {
List<SiteEntity> sites = siteRepository.findAllByActiveTrue();
System.out.println("Method: The Thread name is " + Thread.currentThread().getName());
​
​
for (SiteEntity site : sites) {
System.out.println("Site: " + site.getUrl());
​
System.out.println("Outer: The Thread name is " + Thread.currentThread().getName());
​
List<PhraseEntity> phrases = phraseRepository.findAllActivePhrasesBySite(site.getId());
assertSameSite(phrases, site);
​
final int CHUNK = 10;
List<List<PhraseEntity>> phraseChunks = Lists.partition(phrases, CHUNK);
​
for (List<PhraseEntity> chunk : phraseChunks) {
​
System.out.println("Inner: The Thread name is " + Thread.currentThread().getName());
​
System.out.println(chunk.get(0).getPhrase() + " : " + chunk.get(chunk.size() - 1).getPhrase());
Document doc = sendRequest(chunk, 0);
​
saveManager.save(doc);
}
}
}
}
The service is scraping positions of a web site in a search engine.
For debug purpose I have input each site 100 phrases. That totals to 200 phrases.
This loop can change sites arbitrarily. And the total amount of results can be like 380 (despite the fact that the total amount of phrases is 200).
The reason of that is asynchronicity. I print the names of threads. They change.
Lombok's #Synchronized has not helped
Questions:
Am I right that Spring is asynchronous by default? Documentation: https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#features.task-execution-and-scheduling
How can I execute this loop synchronously?