Use the Java SDK

implementation "ai.leadping:leadping:<version>"
implementation "com.microsoft.kiota:microsoft-kiota-bundle:1.9.3"

<dependency>
  <groupId>ai.leadping</groupId>
  <artifactId>leadping</artifactId>
  <version>VERSION</version>
</dependency>

<dependency>
  <groupId>com.microsoft.kiota</groupId>
  <artifactId>microsoft-kiota-bundle</artifactId>
  <version>1.9.3</version>
</dependency>

import ai.leadping.openapi.LeadpingOpenApiClient;
import com.microsoft.kiota.authentication.ApiKeyAuthenticationProvider;
import com.microsoft.kiota.authentication.ApiKeyLocation;
import com.microsoft.kiota.http.OkHttpRequestAdapter;

String credential = System.getenv("LEADPING_API_KEY");
if (credential == null || credential.isBlank()) {
    throw new IllegalStateException("LEADPING_API_KEY is not set.");
}

var authProvider = new ApiKeyAuthenticationProvider(
        "Bearer " + credential,
        "Authorization",
        ApiKeyLocation.HEADER,
        "api.leadping.ai");
var client = new LeadpingOpenApiClient(new OkHttpRequestAdapter(authProvider));
var lead = client.leads().byId("lead-id").get();
if (lead == null) {
    throw new IllegalStateException("Leadping returned no lead.");
}
System.out.println(lead.getId());

var source = client.sources().byId("source-id").get();