How do you set indexer to manual in magento2?
I do not see any option under bin/magento
There's no such thing as manual indexing on Magento 2 anymore.
The two modes available are:
To change the indexing mode via the CLI you can run:
magento indexer:set-mode {schedule|realtime} [indexer]
For example:
magento indexer:set-mode schedule catalog_category_product catalog_product_category