function main(projectId, templateName) {
  // [START compute_template_create]
  /**
   * TODO(developer): Uncomment and replace these variables before running the sample.
   */
  // const projectId = 'YOUR_PROJECT_ID';
  // const templateName = 'your_template_name';

  const compute = require('@google-cloud/compute');

  // Create a new instance template with the provided name and a specific instance configuration.
  async function createTemplate() {
    const instanceTemplatesClient = new compute.InstanceTemplatesClient();

    const [response] = await instanceTemplatesClient.insert({
      project: projectId,
      instanceTemplateResource: {
        name: templateName,
        properties: {
          disks: [
            {
              // The template describes the size and source image of the boot disk
              // to attach to the instance.
              initializeParams: {
                diskSizeGb: '250',
                sourceImage:
                  'projects/debian-cloud/global/images/family/debian-11',
              },
              autoDelete: true,
              boot: true,
            },
          ],
          machineType: 'e2-standard-4',
          // The template connects the instance to the `default` network,
          // without specifying a subnetwork.
          networkInterfaces: [
            {
              // Use the network interface provided in the networkName argument.
              name: 'global/networks/default',
              // The template lets the instance use an external IP address.
              accessConfigs: [
                {
                  name: 'External NAT',
                  type: 'ONE_TO_ONE_NAT',
                  networkTier: 'PREMIUM',
                },
              ],
            },
          ],
        },
      },
    });
    let operation = response.latestResponse;
    const operationsClient = new compute.GlobalOperationsClient();

    // Wait for the create operation to complete.
    while (operation.status !== 'DONE') {
      [operation] = await operationsClient.wait({
        operation: operation.name,
        project: projectId,
      });
    }

    console.log('Instance template created.');
  }

  createTemplate();
  // [END compute_template_create]
}
Creates a new instance template with the provided name and a specific instance configuration.

@param {string} projectId - Project ID or project number of the Cloud project you use.
@param {string} templateName - Name of the new template to create.