Magento2 Category Thumbnail Image

The Category Thumbnail Image extension helps you to add Category Thumbnail Image

Installation Instruction

• Copy the content of the repo to the app/code
• Run command: php bin/magento setup:upgrade
• Run command: php bin/magento setup:static-content:deploy
• Now flush cache: php bin/magento cache:flush

REF URL: https://webkul.com/blog/add-custom-image-attribute-category-magento-2/