I’m using Google Calendar API to update google calendar events by using batch request I can perform delete and insert and update operations using batch request but when I use patch method using batch request im getting 403 RateLimit error, not sure why, other methods works fine in batch request but not in case for PATCH method.

I also used Exponential Backoff method still not working, this is the code I used.

Thank you for your Time.

try {
      const chunkSize = 100; // Google Calendar API allows a maximum of 1000 request to be processed at once
      let retryDelay = 1000; // Start with a 1 second delay

      for (let i = 0; i < eventsToDelete.length; i += chunkSize) {
        const chunk = eventsToDelete.slice(i, i + chunkSize);

        let retries = 0;
        const maxRetries = 5;

        while (retries < maxRetries) {
          try {
            // Create a batch request to delete all events in the chunk
            const boundary = `batch_${uuidv4()}`;
            let body = '';

            chunk.forEach(event => {
              body +=
                `--${boundary}rn` +
                'Content-Type: application/httprn' +
                `Content-ID: <${event.id}>rnrn` +
                `DELETE /calendar/v3/calendars/${calendarId}/events/${event.id} HTTP/1.1rn` +
                `Authorization: Bearer ${oAuth2Client.credentials.access_token}rnrn`;
            });

            body += `--${boundary}--`;

            const response = await axios.post('https://www.googleapis.com/batch/calendar/v3', body, {
              headers: {
                'Content-Type': `multipart/mixed; boundary="${boundary}"`,
                Authorization: `Bearer ${oAuth2Client.credentials.access_token}`,
              },
            });

            if (response.status === 200) {
              // If successful, reset the retry delay
              retryDelay = 1000;
              break;
            }
          } catch (error) {
            console.log('Error from deleting this and follwing events', error.message);
            // If rate limited, wait for the retry delay then double it
            if (error.message === 'Rate Limit Exceeded') {
              await new Promise(resolve => setTimeout(resolve, retryDelay));
              retryDelay *= 2;
              retries++;
            } else {
              // If the error is something else, rethrow it
              throw error;
            }
          }

          if (retries === maxRetries) {
            throw new Error('Max retries reached');
          }
        }
      }