when we complete project then we send it by email or other?
Firstly, I would highly recommend you read the fiverr terms of service (the terms and conditions that you had to tick to say you read and understood when you signed up for the platform) which state that you are NOT allowed to contact anyone outside of fiverr.
If you want to know more about working on fiverr - you can check the fiverr support area or here: https://sellers.fiverr.com/en/article/how-to-start-selling-on-fiverr
Thanks for your reply
You can deliver the completed project via Fiverr Delivery, You can attach your delivery there.
Please check the image below. A Max Size of 1 GB is permitted if the file size exceeds than 1 GB you can use third party file upload sites and provide URLs for download to the buyer.