You can install this module in two ways:
First Way
Create directory structure "app/code/Ecomteck/DeliveryDate"
Download all files from there Github Module Link
Upload all files inside the DeliveryDate directory
Then run the below commands on Magento root.
php bin/magento setup:upgrade
php bin/magento setup:di:compile
**For production mode:**
php bin/magento setup:static-content:deploy
**For developer mode:**
php bin/magento setup:static-content:deploy -f
php bin/magento cache:clean
Second Way
Install Module by Composer:
Run below commands on Magento root.
composer require ecomteck/module-delivery-date
php bin/magento setup:upgrade
php bin/magento setup:di:compile
**For production mode:**
php bin/magento setup:static-content:deploy
**For developer mode:**
php bin/magento setup:static-content:deploy -f
php bin/magento cache:clean